WASHINGTON (Reuters) - The United States said on Wednesday that it was removing Turkey from the F-35 fighter jet program, a move long threatened and expected after Ankara began accepting delivery of an advanced Russian missile defense system last week.

The first parts of the S-400 air defense system were flown to the Murted military air base northwest of Ankara on Friday, sealing NATO ally Turkey's deal with Russia, which Washington had struggled for months to prevent.

"The U.S. and other F-35 partners are aligned in this decision to suspend Turkey from the program and initiate the process to formally remove Turkey from the program," Ellen Lord, the undersecretary of defense for acquisition and sustainment, told a briefing.

Turkey's foreign ministry said the move was unfair and could affect relations between the two countries.

Lord said moving the supply chain for the advanced fighter jet would cost the United States between $500 million and $600 million in non-recurring engineering costs.

Turkey makes more than 900 parts of the F-35, she said, adding the supply chain would transition from Turkish to mainly U.S. factories as Turkish suppliers are removed.

"Turkey will certainly and regrettably lose jobs and future economic opportunities from this decision," Lord said. "It will no longer receive more than $9 billion in projected work share related to the F-35 over the life of the program."

The F-35 stealth fighter jet, the most advanced aircraft in the U.S. arsenal, is used by NATO and other U.S. allies.

Washington is concerned that deploying the S-400 with the F-35 would allow Russia to gain too much inside information about the aircraft's stealth system.

"The F-35 cannot coexist with a Russian intelligence collection platform that will be used to learn about its advanced capabilities," the White House said in a statement earlier on Wednesday.

Washington had long said the acquisition of the S-400 might lead to Turkey's expulsion from the F-35 program.

After the Pentagon announcement, Turkey's foreign ministry said in a statement: "We invite the United States to return from this mistake which would open irreparable wounds in strategic relations."

NATO Secretary General Jens Stoltenberg, speaking at the Aspen Institute's annual security forum in Aspen, Colorado, said he was concerned at Turkey's expulsion from the F-35 program.

But while the S-400 could not become part of NATO's shared air and missile defenses, he said, Turkey has aircraft and radars that would remain part of the system.

"The S-400, the Russian air defense system, it’s not possible to integrate into the integrated NATO air defense and missile system, which is about sharing, you know, radar picture, about joint air policing, which is about shared capabilities. And Turkey has not asked for that," Stoltenberg said.

The S-400 acquisition is one of several issues that have frayed ties between the two allies, including a dispute over strategy in Syria east of the Euphrates River, where the United States is allied with Kurdish forces that Turkey views as foes.

The Pentagon had already laid out a plan to remove Turkey from the program, which included halting training for Turkish pilots on the aircraft.

Lord said all the Turkish F-35 pilots and personnel had "firm plans" to leave the United States and were scheduled to leave by July 31.

Turkey will no longer be able to buy the 100 F-35s it had agreed to purchase.

"These would likely have been delivered at an annual rate of 8-12 aircraft/year through the 2020s," Byron Callan, an analyst at Capital Alpha Partners, said in a research note on Wednesday.

The jet's prime contractor, Lockheed Martin Corp and the jet's program office at the Pentagon "should be able to re-market those delivery positions," Callan said.

Lockheed Martin spokeswoman Carolyn Nelson said: "Over the last several months we've been working to establish alternative sources of supply in the United States to quickly" adjust for the loss of Turkey's contribution to the program.

The United States is considering expanding sales of the jets to five other nations, including Romania, Greece and Poland, as European allies bulk up their defenses in the face of a strengthening Russia.

David Trachtenberg, the deputy undersecretary of defense for policy, told reporters at the briefing that the United States still valued its relationship with Turkey.

"Our strategic partnership continues, but as I said, this is a specific response to a specific action," Trachtenberg said. </s> Turkey will not be getting the F-35 Lightning II fifth-generation stealth fighters from the United States of America because it has bought the S-400 Triumf air defence missile system from Russia. US President Donald Trump on Tuesday declared that Turkey cannot buy the over 100 F-35 Lightning II fighters that the country had ordered from American defence major Lockheed Martin.

"Turkey has also ordered over a hundred F-35 planes - substantially over a hundred - and they have plans to order more. But because they have a system of missiles that's made in Russia, they're now prohibited from buying over a hundred planes. I would say that Lockheed isn’t exactly happy. That's a lot of jobs," Trump said during a press conference at the White House on Tuesday.

"So what happens is we have a situation where Turkey is very good with us. Very good. And we are now telling Turkey that, because you have really been forced to buy another missile system, we’re not going to sell you the F-35 fighter jets. It's a very tough situation that they're in. And it’s a very tough situation that we’ve been placed in - the United States. With all of that being said, we’re working through it. We’ll see what happens. But it’s not really fair. They wanted to buy - I don’t stick up for countries. I don’t stick up for Turkey. I don’t stick up - other than I've had a good relationship with President Erdogan," said the US President.

Till July 16, 2019, 12 Russian aircraft have landed in Turkey with S-400 Triumf missile systems. Turkey, which is a member of the F-35 Lightning II development programme, has ordered 116 jets but the US has refused to deliver the stealth fighters. Even the four F-35s that were delivered to the Turkish Air Force inventory are being held in the US after Ankara announced that it would go ahead with buying the S-400 Triumf missiles despite the threat of sanctions and action by America.

Trump also blamed his predecessor and former US president Barack Obama for pushing Turkey towards Russia for its defence needs. "The Obama administration would not sell them the Patriot missiles. They need the Patriot missiles for defense. They would not sell them, under any circumstance," he claimed.

"And Turkey tried very hard to buy them, and they wouldn’t sell them, and this went on for a long period of time. And it was as soon as they found out that they were going to have to buy the missiles - a comparable missile - not as good a missile, but a comparable, almost, missile from Russia, all of a sudden everybody started rushing and saying to Turkey, "Okay, we'll sell you the Patriot missile." It was only when they found out they couldn’t get it, then, they say, "Let’s go, we’ll sell you the Patriot missile." But, by that time, Turkey had already signed and paid a lot of money to Russia for the missile system that they were not allowed to buy here, foolishly - because Turkey is a NATO member," said Trump.

According to the US defence officials, the S-400 Triumf missiles cannot operate with NATO's air defence systems as the two systems are incompatible and the Russian platform may also compromise operations of the F-35. </s> ANKARA, Turkey (AP) — NATO ally Turkey is being kicked out of the U.S.-led F-35 fighter jet program over its decision to buy the Russian-made S-400 air defense system.

The White House said Turkey's decision to buy the Russian system "renders its continued involvement with the F-35 impossible" while the Pentagon suspended Turkey from the program and said it will be removed as a partner in making the planes.

Here is a look at the rift between the NATO allies over the deal.

The Russian-made S-400 Triumph is a sophisticated long-range surface-to-air missile defense system capable of striking enemy aircraft and cruise missiles. It has a range of 400 kilometers (250 miles). The system can simultaneously engage multiple targets and is capable of shooting down ballistic missile warheads along with aircraft and cruise missiles.

Turkey reached a deal with Russia for the purchase of two batteries at a reported cost of $2.5 billion in December 2017. Erdogan has said the systems will both be operational by April 2020. Officials have refused to disclose where the systems will be deployed.

WHY IS NATO-MEMBER TURKEY BUYING THE RUSSIAN SYSTEM?

Turkey, which neighbors trouble spots such as Syria, Iraq and Iran, has long sought to address shortcomings concerning its air defenses. It says it was forced to negotiate with Russia for the purchase of the S-400s after the U.S. refused to sell the American-made Patriot system. Turkey has also argued that the S-400 is one of the best available systems and says the deal with Russia involves joint production and technology transfers which meet its long-term goals of defense self-sufficiency.

The United States says talks on a potential Patriot deal failed over Turkey's insistence on technology transfer rights that would have allowed it eventually to make the missiles themselves. This ran against U.S. manufacturer's propriety interests in addition to any national security concerns.

Turkey's rapprochement with Russia and its decision to buy the Russian system also coincides with growing Turkish mistrust of the U.S. over its policies in Syria. More specifically, Turkey has been angered with U.S. support for a Syrian Kurdish group in Syria that is affiliated with Kurdish rebels fighting Turkey.

Turkey also distrusts Washington because Muslim cleric Fethullah Gulen, whom Ankara says orchestrated a 2016 failed coup, remains free in the U.S. Gulen denies involvement in the coup attempt.

WHY DOES THE US OBJECT TO TURKEY'S S-400 PURCHASE?

The U.S. says the S-400s can't be integrated into the NATO system and pose a threat to the F-35 fighter jet program. Washington is concerned that system could be used to gather data on the capabilities of the F-35, and that the sensitive information could end up in Russian hands.

Turkey insists the U.S. fighter jets won't be compromised because the S-400 and F-35s will be deployed in separate locations and the S-400 will be under Turkish control. Turkey has also proposed the setting up of a joint working group to study how the S-400 system would interact with the fighter jets.

WHAT DOES TURKEY'S SUSPENSION FROM THE F-35 PROGRAM MEAN?

Pentagon's chief weapons buyer, Ellen Lord, told a news conference that the U.S. has suspended Turkey from the F-35 program and is beginning the process of its formal removal. The process of removing Turkey permanently is underway and should be completed by March 31, she said.

Lord said Turkey, which makes more than 900 components of the stealth aircraft, stands to lose $9 billion in future earnings as its parts supplier.

Washington has already suspended a program of F-35 flight training for Turkish student pilots and instructor pilots at Luke Air Force Base in Arizona and given those personnel a July 31 deadline to leave the U.S.

Separately, the U.S. has also warned that Turkey could face economic sanctions under the Countering America's Adversaries Through Sanctions Act (CAATSA). Previous U.S. sanctions on Turkey over its detention of an American pastor had caused a slide in the Turkish lira.

However, President Donald Trump, who has struck cordial relations with Erdogan, has taken a more conciliatory approach to Turkey, raising hopes in the country that it will avert harsh penalties. The U.S. State Department this week has been silent on whether those sanctions will be imposed.

Turkey says it is prepared for U.S. sanctions and can impose countermeasures of its own. Some media reports have said Turkey could launch an operation into northeast Syria in reaction to the U.S. sanctions.

HOW DOES THE DEAL AFFECT NATO?

Turkey has been a key member of the NATO alliance since it joined in 1952. It has the second-largest army in NATO after the U.S. and has been protecting the alliance's southeastern flank for years.

It is unprecedented for a NATO ally to purchase such advanced defense weaponry from Russia, which is considered to be NATO's main adversary. Turkey's deal with Russia has raised questions over whether the country is moving under Russia's influence and over its future membership.

However, NATO Secretary General Jens Stoltenberg has said Turkey's contributions to NATO and the alliance's cooperation with Ankara "is much broader" than the F-35 issue. He said: "I'm not underestimating the difficulty related to (the) S-400, but I'm saying that Turkey, as a NATO member, is much more than S-400."

Turkish Defense Minister Hulusi Akar has said the purchase "was not an option but rather a necessity" because of Turkey's security concerns. He stressed that there was no change in Turkey's "strategic orientation." </s> US removing Turkey from F-35 program after its Russian missile defense purchase

WASHINGTON: The United States said on Wednesday that it was removing Turkey from the F-35 fighter jet program, a move that had been long threatened and expected after Ankara began accepting delivery of an advanced Russian missile defense system last week.

The first parts of the S-400 air defense system were flown to the Murted military air base northwest of Ankara on Friday, sealing Turkey’s deal with Russia, which Washington had struggled for months to prevent.

“The U.S. and other F-35 partners are aligned in this decision to suspend Turkey from the program and initiate the process to formally remove Turkey from the program,” said Ellen Lord, the under secretary of defense for acquisition and sustainment.

“The United States is spending between $500 and $600 million in non-recurring engineering in order to shift the supply chain,” she said.

Used by NATO and other U.S. allies, the F-35 stealth fighter jet is the world’s most advanced jet fighter. Washington is concerned that deploying the S-400 with the F-35 would allow Russia to gain too much inside information of the stealth system.

“The F-35 cannot coexist with a Russian intelligence collection platform that will be used to learn about its advanced capabilities,” the White House said in a statement earlier on Wednesday.

Washington has long said the acquisition may lead to Turkey’s expulsion from the F-35 program.

The Pentagon had already laid out a plan to remove Turkey from the program, including halting any new training for Turkish pilots on the advanced aircraft.

“The situation with Turkey is a government-to-government matter and we’ll comply with any guidance issued by the United States Government,” said a spokesperson for Lockheed Martin Corp (LMT.N), the prime contractor on the jet. </s> The White House confirmed Wednesday that Turkey would be excluded from the F-35 stealth fighter jet program after it purchased a Russian missile defense system in defiance of warnings from Western allies

Washington, (UrduPoint / Pakistan Point News - APP - 18th Jul, 2019 ) :The White House confirmed Wednesday that Turkey would be excluded from the F-35 stealth fighter jet program after it purchased a Russian missile defense system in defiance of warnings from Western allies.

"Unfortunately, Turkey's decision to purchase Russian S-400 air defense systems renders its continued involvement with the F-35 impossible," White House spokeswoman Stephanie Grisham said in a statement.

The US-made F-35 Joint Strike Fighter "cannot coexist with a Russian intelligence collection platform that will be used to learn about its advanced capabilities," she added.

Turkey's foreign ministry termed the move "unfair," saying in a statement that "this one-sided step neither complies with the spirit of alliance nor is it based on legitimate reasons." Grisham said that Washington had made "multiple" offers of its own Patriot missile defense system to Turkey, but Ankara went ahead and acquired the S-400, running counter to a NATO pledge to avoid adopting Russian systems.

"This will have detrimental impacts on Turkish interoperability with the Alliance," she said.

Grisham added that the United States "still greatly values" its strategic relationship with Ankara and would "continue to cooperate with Turkey extensively, mindful of constraints due to the presence of the S-400 system in Turkey." - Trump:'tough situation' - The announcement came five days after Turkey began taking delivery of the Russian missile system, shrugging off two years of warnings from the United States and other NATO allies that it could imperil their relationship.

The US action will lock out a number of Turkish manufacturers that were producing parts and components for the F-35, and block Turkey's plans to purchase about 100 of the advanced fighters.

On Tuesday, President Donald Trump declined to criticize Turkey for the S-400 purchase, falsely charging that President Recep Tayyip Erdogan was unfairly forced into the move by his White House predecessor Barack Obama.

"It's a very tough situation that they're in and it's a very tough situation that we've been placed in.

.. With all of that being said, we're working through it -- we'll see what happens," he said.

Trump rued the loss of the sale of up to 100 F-35s to Turkey, saying manufacturer Lockheed Martin would suffer.

"Because they have a system of missiles that's made in Russia, they're now prohibited from buying over 100 planes. I would say that Lockheed isn't exactly happy. That's a lot of jobs," Trump said.

- Turkish manufacturers dropped - At the Pentagon, officials said operations were already underway to move the production of around 900 parts Turkey was to provide for the F-35s to suppliers in the United States and other countries.

Turkish F-35 technicians and pilots training in the United States would also be sent back by the end of this month.

"Turkey's purchase of the S-400 is inconsistent with its commitments to NATO," said Under Secretary of Defense Ellen Lord.

"Turkey will certainly and regrettably lose jobs and future economic opportunities from this decision," she said.

Turkey had work commitments worth $1 billion to supply the F-35 program, and could have expected a total of $9 billion in orders over the life of the program, according to Lord.

In addition, the US Congress has required countries that make significant purchases of Russian defense equipment to be subjected to punitive sanctions.

The State Department said Wednesday that no decision has been made yet on sanctions over the S-400 deal.

- 'Still a strong ally' - David Trachtenberg, deputy undersecretary at the US Defense Department, repeated that Turkey remains a strong ally of the United States and would still join NATO exercises.

"We will continue to participate with Turkey in multilateral exercises to improve readiness and interoperability, including upcoming exercises in Georgia, Germany and Ukraine," he told reporters.

Asked if Turkey could be ejected from NATO after nearly seven decades as a member, he replied: "That's a decision for the NATO alliance... That's not for us here to decide." LOCKHEED MARTIN </s> The United States on Friday raised the stakes in its standoff with Turkey over Ankara’s deal to acquire a Russian air defense system, laying out a plan to remove the NATO ally from the F-35 fighter jet program that includes halting any new training for Turkish pilots on the advanced aircraft.

Acting U.S. Defense Secretary Patrick Shanahan sent a letter to his Turkish counterpart, seen by Reuters on Friday, that laid out the steps to “unwind” Turkey from the program.

Reuters on Thursday first reported the decision to stop accepting more Turkish pilots for training in the United States, in one of the most concrete signs that the dispute between Washington and Ankara is reaching a breaking point.

The United States says Turkey’s acquisition of Russia’s S-400 air defense system poses a threat to the Lockheed Martin Corp F-35 stealthy fighters, which Turkey also plans to buy. The United States says Turkey cannot have both.

Shanahan’s letter explicitly states there will be “no new F-35 training.” It says there were 34 students scheduled for F-35 training later this year.

“This training will not occur because we are suspending Turkey from the F-35 program; there are no longer requirements to gain proficiencies on the systems,” according to an attachment to the letter that is titled, “Unwinding Turkey’s Participation in the F-35 Program.”

In his letter, Shanahan warns that training for Turkish personnel on the F-35 at Luke Air Force Base and Eglin Air Force Base will be discontinued at the end of July.

“This timeline will enable many, but not all, Turkish F-35 students currently training to complete their courses prior to departing the United States by July 31, 2019,” Shanahan said in his letter, which noted: “You still have the option to change course on the S-400.”

Turkey has expressed an interest in buying 100 of the fighters, which would have a total value of $9 billion at current prices.

If Turkey were removed from the F-35 program, it would be one of the most significant ruptures in recent history in the relationship between the two allies, experts said.

Strains in ties already extend beyond the F-35 to include conflicting strategy in Syria, Iran sanctions and the detention of U.S. consular staff in Turkey.

The disclosure of the decision on the pilots follows signs that Turkey is moving ahead with the S-400 purchase.

Defense Minister Hulusi Akar said on May 22 that Turkish military personnel were receiving training in Russia to use the S-400, and that Russian personnel may go to Turkey.

The head of Russian state conglomerate Rostec, Sergei Chemezov, said the country would start delivering S-400 missile systems to Turkey in two months, the Interfax news agency reported.

President Tayyip Erdogan said on Tuesday it was “out of the question” for Turkey to back away from its deal with Moscow.

Erdogan said the United States had not “given us an offer as good as the S-400s.”

The Turkish lira declined as much as 1.5% on Friday before recovering some losses. The currency has shed nearly 10% of its value against the dollar this year in part on fraying diplomatic ties and the risk of U.S. sanctions if Turkey accepts delivery of the S-400s.

Kathryn Wheelbarger, one of the Pentagon’s most senior policy officials, said last week that Turkey’s completion of the transaction with Russia would be “devastating,” dealing heavy blows to the F-35 program and to Turkish interoperability within the NATO alliance.

“The S-400 is a Russian system designed to shoot down an aircraft like the F-35,” said Wheelbarger, an acting assistant secretary of defense. “And it is inconceivable to imagine Russia not taking advantage of that (intelligence) collection opportunity.” </s> The United States has given Turkey a deadline of July 31 to reverse its purchase of a Russian missile-defense system or face the loss of subcontracting work on the U.S.-led F-35 fighter jet project.

 

 Ellen Lord, U.S. undersecretary of defense for acquisition and sustainment, also told reporters on June 8 that Turkish pilots training in the United States on F-35 warplanes being sold to Ankara will be expelled if the missile deal is not called off.

 

 She said the deadline "will allow sufficient time for Turkish personnel associated with the F-35 program to be reassigned and depart the United States...to facilitate an orderly cessation of Turkish participation."

 

 Acting U.S. Defense Secretary Patrick Shanahan sent a letter to his Turkish counterpart that explained the measures to remove Turkey from the program unless Ankara changes course.

 

 Washington and its allies consider Russia’s S-400 missile system to be incompatible with NATO systems and a threat to the F-35 fighter jets.

 

 The United States has urged Ankara to back off its purchase of the system and has turned up the heat as its delivery date has neared.

 

 President Recep Tayyip Erdogan has repeatedly said his country was "determined" to proceed with the Russia purchase, which he has long labeled a “done deal.”

 

 Turkey, a NATO ally of the United States, had already sent personnel to Russia to start training with the S-400. It also has at least two pilots training in the United States to fly the F-35 – of which Turkey has purchased 100 for its own military’s use.

 

 Turkey has spent billions to gear up its industry to participate in parts production related to the F-35s. Companies in the country make hundreds of parts for the warplane, largely for the aircraft's landing gear and center fuselage.

 

 Lord said Turkey's participation would be finished by early 2020 if it does not reverse the S-400 deal.

 

 "Turkey still has the option to change course," she said.

 

 "If Turkey does not accept delivery of the S-400, we will enable Turkey to return to normal," she said.

 

 The F-35s are designed to operate in sync and with NATO systems, including antimissile defenses, raising fears that Russia could adjust the S-400's capacities against the Western Alliance through information gathered in dealing with Turkey.

 

 U.S. officials have pressed Turkey to switch to the American-made Patriot air defense system, telling Ankara that would allow it to continue participation in the F-35 program.

 

 Erdogan said he told the United States that Ankara would consider buying Patriots only if Washington's conditions for a deal were as good as Moscow's offer.

 

 "But unfortunately we haven't received a positive proposal from the American side on the subject of Patriots like the S-400s from Russia," he said.

 

 Shanahan said he believed the U.S. offer for the Patriots was "very competitive."

With reporting by Reuters, AFP, and AP </s> The United States on Friday raised the stakes in its standoff with Turkey over Ankara’s deal to acquire a Russian air defense system, laying out a plan to remove the NATO ally from the F-35 fighter jet program that includes immediately halting any new training for Turkish pilots on the advanced aircraft.

Acting U.S. Defense Secretary Patrick Shanahan sent a letter to his Turkish counterpart, seen by Reuters on Friday, that laid out the steps to remove Turkey from the program unless Turkey changes course.

Reuters on Thursday first reported the decision to stop accepting more Turkish pilots for training in the United States, in one of the most concrete signs that the dispute between Washington and Ankara is reaching a breaking point.

The United States says Turkey’s acquisition of Russia’s S-400 air defense system poses a threat to the Lockheed Martin Corp. F-35 stealthy fighters, which Turkey also plans to buy. The United States says Turkey cannot have both.

Shanahan’s letter explicitly states there will be “no new F-35 training.” It says there were 34 students scheduled for F-35 training later this year.

“This training will not occur because we are suspending Turkey from the F-35 program; there are no longer requirements to gain proficiencies on the systems,” according to an attachment to the letter that is titled, “Unwinding Turkey’s Participation in the F-35 Program.”

Turkish personnel already in the United States will see their training on the F-35 discontinued at the end of July.

In his letter, Shanahan also warned Ankara that its deal with Moscow risked undermining its ties to NATO, hurting the Turkish economy and creating over-dependence on Russia.

“You still have the option to change course on the S-400,” Shanahan wrote.

The Turkish lira declined as much as 1.5 percent on Friday before recovering some losses. The currency has shed nearly 10 percent of its value against the dollar this year in part on fraying diplomatic ties and the risk of U.S. sanctions if Turkey accepts delivery of the S-400s.

Turkey is one of the core partners in the F-35 program and expressed an interest in buying 100 of the fighters, which would have a total value of $9 billion at current prices.

Turkish companies produce some 937 parts of the F-35, largely for the aircraft’s landing gear and center fuselage, the Pentagon says. The United States is now planning to move that production elsewhere, ending Turkey’s manufacturing role by early next year.

The Pentagon believes that it can minimize the impact on the broader program if Turkey abides by the U.S. timeline.

“What we are doing is working to do a very disciplined and graceful wind-down,” Ellen Lord, an under secretary of defense, told reporters at the Pentagon.

But if Turkey were removed from the F-35 program, the ramifications would be felt far beyond the Turkish air force. It would be one of the most significant ruptures in recent history in the relationship with the United States, experts said.

Strains in ties between the United States and Ankara already extend beyond the F-35 to include conflicting strategy in Syria, Iran sanctions and the detention of U.S. consular staff in Turkey.

Still, Turkey seems to be moving ahead with the S-400 purchase, regardless of the U.S. warnings. President Tayyip Erdogan said on Tuesday it was “out of the question” for Turkey to back away from its deal with Moscow.

Defense Minister Hulusi Akar said on May 22 that Turkish military personnel were receiving training in Russia to use the S-400, and that Russian personnel may go to Turkey.

The head of Russian state conglomerate Rostec, Sergei Chemezov, was quoted as saying on Friday that the country would start delivering S-400 missile systems to Turkey in two months.

Erdogan said the United States had not “given us an offer as good as the S-400s.”

Still, Lord held out hope for Turkey, noting that none of the U.S. decisions so far were irreversible.

“We’re hopeful that they will stop the acquisition of the S-400. We would very much like them to stay in the (F-35) program,” Lord said. </s> Alwaght- The US once again has threatened Turkey not to by Russia to buy an S-400 missile defense system if it wants to continue participating in the F-35 fighter jet program.

Ellen Lord, Under Secretary of Defense for Acquisition and Sustainment, told reporters on Friday that agreements with Turkish firms sub-contracted for manufacturing the F-35 stealth warplane will be cancelled unless Ankara gives up on the S-400 system by July 31.

The deadline "will allow sufficient time for Turkish personnel associated with the F-35 program to be reassigned and depart the United States... to facilitate an orderly cessation of Turkish participation."

Two unnamed US officials told Reuters earlier on Friday that Washington would no longer accept any additional Turkish pilots to train on F-35 fighter jets.

Lord, however, said that even Turkish pilots currently training in the United States on the F-35 will be expelled too.

Currently, four Turkish pilots are receiving training on F-35 fighter jets at Luke Air Force Base in Arizona and two more are working as instructors at the base. An additional 20 Turkish aircraft maintainers are also participating in the program, according to the US military.

Lord justified the US ultimatum by the fact that Turkey, a NATO ally of the United States, already has its personnel in Russia waiting to be trained with the S-400.

US officials previously said they wanted Ankara to opt for the American Patriot system instead, saying that option would allow the F-35 program to continue.

Turkey, which plans to buy 100 US F-35s, said it told the US that Ankara would buy Patriots only if Washington's conditions of delivery were as positive as Moscow's.

"But unfortunately we haven't received a positive proposal from the American side on the subject of Patriots like the S-400s from Russia," Turkish President Recep Tayyip Erdogan said.

Acting US Defense Secretary Patrick Shanahan said he, in a letter, had informed his Turkish counterpart Hulusi Akar of Washington's new decision.

The US offer for the Patriots was "very competitive," Shanahan told reporters.

The S-400 is an advanced Russian missile system designed to detect, track, and destroy planes, drones, or missiles as far as over 400 kilometers away. It has previously been sold only to China and India.

Ankara is striving to boost its air defense, particularly after Washington decided in 2015 to withdraw its Patriot surface-to-air missile system from Turkish border with Syria, a move that weakened Turkey’s air defense.

Ankara has been critical of Washington for supporting Kurdish groups in Syria that he says are responsible for terror attacks inside Turkey, among other issues.
The United States removes NATO ally Turkey from the Joint Strike Fighter program, following the country's acquisition of the Russian S-400 missile system. Turkey had planned to buy 100 F-35 Lightning II jets.