Stephen Harper is heading to a crucial summit of NATO leaders where the Western military alliance will give itself the power to respond to threats more quickly in the face of Russia’s continued effort to destabilize and break up Ukraine. 
 
 NATO leaders are set to approve a rapid-reaction military force, drawn from their respective defence capabilities, that could be deployed to a crisis in Eastern Europe within two days, alliance officials say. This “spearhead” unit would have a permanent command centre staffed by rotating alliance members as well as supply depots located in various regions so troops would not have to fly in all their equipment. 
 
 “This spearhead … could include several thousand troops, ready to respond where needed with air, sea and special-forces support,” NATO Secretary-General Anders Fogh Rasmussen told a news conference Monday in Brussels. 
 
 NATO’s existing response force takes five days for the first units to arrive. 
 
 This summit, originally meant to mark the end of the NATO-led mission in Afghanistan, will instead signal a shift to the defence of Europe as the alliance’s central concern once more. 
 
 Mr. Harper departed Ottawa Tuesday morning for the U.K. He'll first visit London‎ to promote bilateral trade and investment in light of the Canada-European Union free-trade deal and then proceed to a Cardiff-area resort in Wales for talks with NATO member country leaders. 
 
 The rapid-response force would not help Kiev, which has been battling pro-Moscow rebels for months after Russia unilaterally seized Crimea this spring and now has Vladimir Putin pressuring it to discuss “statehood” for southeast regions of Ukraine. 
 
 Canadian officials, speaking on background, made it clear that the North Atlantic Treaty Organization has no plans to deploy troops to Ukraine, which is currently taking steps to apply for membership in the Western military alliance. It’s unclear if, or when, Kiev might be admitted into the club, which has an agreement to defend member countries against attack. 
 
 NATO appears to have shelved a proposal to permanently station alliance troops in new bases along its eastern flank, a measure sought by members such as Poland as a means of providing a deterrent to further Russian aggression. Member countries such as Germany rejected the idea because such a move could provoke Moscow. 
 
 The rapid-reaction force, which could serve as a deterrent in its own right, appears to be a compromise. NATO officials said the force could grow from a small number to as large as a brigade, which would mean between 3,000 and 5,000 troops. It means NATO would be ready to quickly respond to Russian aggression that goes beyond Ukraine, which the alliance has confirmed with satellite imagery is now fighting Russian troops, and not just pro-Moscow rebels, on its own soil. 
 
 Canada will be asked to contribute soldiers and equipment to NATO's new high-alert force. 
 
 But the Canadian government refused to say Monday whether it would contribute on a regular basis to this rapid-reaction force, with officials saying only they would “consider all measures accordingly and look forward to discussions at the summit.” 
 
 The alliance, said Fen Hampson, director of the Global Security and Politics program at the Centre for International Governance Innovation in Waterloo, Ont., “is divided between its East European and Baltic members who are deeply worried that Putin won’t stop with Ukraine if he gets what he wants, and its major powers, Germany, the U.K. and France, who continue to believe that Putin is amenable to negotiation and persuasion.” 
 
 Canada was also wary of the proposal to permanently station NATO troops in new bases because there was insufficient detail on which allies might pay the bills or contribute troops and what the rules of engagement would be. “None of that was clear,” a Canadian official said. 
 
 The Harper government, expected to go to the polls in 2015, is also balking at a push for NATO countries to boost military spending to at least 2 per cent of gross domestic product. The British government is calling for this commitment at the summit. Britain is among a small minority of NATO members that currently spend 2 per cent or more of GDP on defence, while Canada spends roughly 1 per cent. 
 
 Canadian officials defend their position, saying the NATO pledge goes beyond what Canadian taxpayers would support. They say Canada shouldered a big burden with its decade-long Afghanistan deployment and its contribution to Operation Protector in Libya. 
 
 The Harper government has chopped military spending to balance the books, and a recent study said on an inflation-adjusted basis that Canada’s defence budget is now smaller than it was in 2007. 
 
 Ottawa has a ship, six fighter jets and rotating shifts of Canadian Armed Forces members on training exercises in Europe to help reassure NATO member countries concerned about further Russian aggression in the region. It’s also matched sanctions imposed on Russians and Ukrainians linked to Moscow’s efforts to menace Ukraine. 
 
 Mr. Hampson said the summit marks a watershed moment for the alliance. “NATO is facing its greatest crisis since the Berlin and Cuban crises of the Cold War,” he said. “NATO can show that it is a real alliance that is prepared to stand up to Putin’s incursions, or it can fade into oblivion by issuing more frothy communiqués that commit its members to little.” 
 
 Editor's note: An earlier version of this article stated incorrectly that the next federal election is in 2016. This version has been corrected to say the vote is in 2015. ||||| CARDIFF, Wales — President Obama and Prime Minister David Cameron of Britain have called on NATO to reject “isolationist” impulses and confront the rising terrorist threat posed by Sunni militants in the Middle East, saying the United States and Britain “will not be cowed by barbaric killers.” 
 
 “We will not waver in our determination to confront” the militant group known as the Islamic State in Iraq and Syria, or ISIS, the two leaders wrote in a joint opinion piece published in Thursday’s editions of The Times of London. “If terrorists think we will weaken in the face of their threats they could not be more wrong.” 
 
 Their pointed words came as leaders gathered in Wales for a NATO summit meeting that was intended to focus on responding to Russia’s escalating military intervention in Ukraine. On the sidelines of the meeting, however, American and British efforts to assemble and lead an international coalition against ISIS are expected to predominate. 
 
 “The international community as a whole has an obligation to stop the Islamic State from advancing further,” Anders Fogh Rasmussen, the NATO secretary general, said at a news conference on Thursday. But he noted that there had been no request from Iraq for NATO assistance in confronting the group. 
 
 Continue reading the main story Video 
 
 Mr. Obama and the leaders of Britain, France, Germany and Italy will meet with President Petro O. Poroshenko of Ukraine to discuss the crisis in his country, which will also be the topic of an afternoon meeting where allies will consider sending additional assistance to Kiev. 
 
 Before they met, the Russian foreign minister, Sergey V. Lavrov, warned that Ukraine’s efforts to form an alliance with NATO threatened to short-circuit talks to end the fighting between pro-Russian separatists and government forces in eastern Ukraine. 
 
 Mr. Lavrov, in televised remarks in Moscow, said that discussions between top Ukrainian officials and NATO leaders were “a blatant attempt to derail all the efforts” to reach a negotiated settlement in Ukraine, The Associated Press reported. 
 
 NATO leaders will also discuss winding down the alliance’s combat mission in Afghanistan at the end of the year and shifting it to a training and assistance mission, although details of the transition cannot be finalized until Afghans resolve a disputed presidential election. 
 
 In their joint editorial, Mr. Obama and Mr. Cameron argued that ISIS is as immediate a threat to the security of NATO members as is the behavior of Russia, which they wrote had “ripped up the rule book” by annexing Crimea and sending its troops into Ukraine. Russia has denied any military involvement in Ukraine. 
 
 “Whether it is regional aggression going unchecked or the prospect that foreign fighters could return from Iraq and Syria to pose a threat in our countries, the problems we face today threaten the security of British and American people, and the wider world,” they wrote. 
 
 Mr. Obama and Mr. Cameron argued that NATO must transition to a “more effective security network that fosters stability around the world,” urging member nations to bolster military spending. 
 
 They also called for keeping a “persistent” NATO defensive presence in Eastern Europe to make clear to Russia that the alliance is serious about the defense of all of its members, and expressed support for a rapid-response force — expected to be endorsed by NATO allies this week — including land, air, maritime and special forces “that could deploy anywhere in the world at very short notice.” ||||| Brussels, Belgium (CNN) -- NATO will suspend "all practical civilian and military cooperation" with Russia because of its annexation of Crimea, saying it has seen no sign that Moscow was withdrawing troops from the Ukrainian border. 
 
 Foreign ministers from the 28 members of the Western military alliance met in Brussels on Tuesday for the first time since Russia grabbed the Black Sea peninsula from Ukraine last month, triggering the worst East-West crisis since the Cold War. 
 
 They were discussing ways to boost NATO's military presence in formerly communist central and Eastern Europe to reassure allies worried by Russia's moves. 
 
 After the session, U.S. Secretary of State John Kerry said Russia has challenged truths that only a few weeks ago seemed self-evident: that European borders in the 21st century would not be redrawn by force. 
 
 "It is important for everybody in the world to understand that the NATO alliance takes seriously this attempt to change borders by use of force," he said. "So that is the wake-up call." 
 
 Russia's aggression "is the gravest threat to European security in a generation and it challenges our vision of a Europe whole, free and at peace," NATO Secretary General Anders Fogh Rasmussen told reporters. 
 
 In a joint statement announcing the suspension of cooperation, the ministers said political dialogue in the NATO-Russia Council could continue, "as necessary, at the ambassadorial level and above, to allow us to exchange views, first and foremost on this crisis." 
 
 They said they would review NATO's relations with Russia at their next meeting in June. NATO and Russia have cooperated on an anti-narcotics operation in Afghanistan, counterpiracy and various counterterrorism measures. Rasmussen said cooperation on the anti-narcotics operations would continue. 
 
 A NATO official told CNN the ministers had decided the alliance would develop, as a matter of urgency, "a series of additional measures to reinforce NATO's collective defenses." 
 
 These would include possible deployments and reinforcements of alliance military assets in Eastern European member states, a possible review of training and exercise plans in the near term, a possible increase of the readiness level of the NATO Response Force, and a possible review and update of NATO defense and military plans, the official said. 
 
 Russian troops on border 
 
 Earlier, Rasmussen said he saw no sign that Russia is pulling its forces back from the border with Ukraine. 
 
 "Unfortunately, I cannot confirm that Russia is withdrawing its troops," Rasmussen said at the opening of the two-day meeting. "This is not what we're seeing. And this massive military buildup can in no way contribute to a de-escalation of the situation." 
 
 Concerns are high that Russia, which U.S. officials last week said had about 40,000 troops near the frontier, might seek to enter eastern Ukraine, after it annexed Ukraine's Crimea region last month. 
 
 Russian President Vladimir Putin told German Chancellor Angela Merkel on Monday that he'd ordered a withdrawal of some Russian troops from his country's border area with Ukraine, Merkel's office said. The news prompted U.S. State Department spokeswoman Jen Psaki to say Monday that if the reports were accurate, "it would be a welcome preliminary step." 
 
 On Tuesday, Merkel told reporters: "I can only take what the Russian President has told me. I will, of course, try to find out whether this is perceptible or not perceptible." 
 
 According to Russian state media Monday, one Russian infantry battalion was being moved from the border area to its base deeper in Russia. A battalion would typically number several hundred troops. 
 
 But Rasmussen appeared to quash hopes that the situation might be easing with his remarks Tuesday. His assessment was echoed in Brussels by UK Foreign Secretary William Hague, who said: "We have had some statements or rumors from Russia about pulling back forces from the eastern border of Ukraine. 
 
 "But we haven't seen the evidence of that yet. Of course, we continue to call for that and continue to use every possible diplomatic lead to seek a de-escalation of this crisis." 
 
 Kerry, among those in Brussels for the NATO meeting, also called for a Russian withdrawal in lengthy weekend talks in Paris with his Russian counterpart, Sergey Lavrov. 
 
 What do we know about Russia's troop buildup on Ukraine's border? 
 
 Also Tuesday, the U.S. House gave final congressional approval to legislation that would impose sanctions on Russia for its takeover of Crimea and provide $1 billion in loan guarantees to Ukraine. The bill now goes to President Barack Obama for his signature. 
 
 In a statement, the White House said the President welcomed the move. 
 
 "This legislation will allow us to provide crucial support to Ukraine through loan guarantees that will facilitate access to needed financing to Ukraine as it takes essential steps to restore economic stability and return to growth and prosperity," it read. 
 
 NATO and Ukraine cooperation 
 
 The foreign ministers also met with Ukrainian acting Foreign Minister Andriy Deshchytsia in the latest demonstration of Western support. Moscow does not recognize Ukraine's new government, saying President Viktor Yanukovych was removed in an unconstitutional coup. 
 
 In a joint statement, they called on Moscow "to reverse the illegal and illegitimate 'annexation' of Crimea; to refrain from any further interference and aggressive actions in Ukraine ... and to abide by international law." 
 
 At the same time, NATO and Ukraine announced they would intensify cooperation and promote defense reforms in Ukraine through training and other programs. 
 
 Rasmussen told reporters the ministers agreed to help Ukraine make its military "more professional and more effective" and provide advice on how it can defend its infrastructure. "A possibility is also deployment of mobile training teams as and when appropriate," he said. 
 
 Pressed on how NATO was prepared to help Ukraine improve its military, Rasmussen cited enhanced military exercises as an example. 
 
 As the talks got under way, Russia's Foreign Ministry had warned Ukraine against seeking integration into the defense alliance. 
 
 Discussion of the issue while Yanukovych was in power "led to freezing of Russian-Ukrainian political communications, to headaches in the relationship between NATO and Russia and, what is the most dangerous, to the deepening of the split of Ukrainian society, the majority of which doesn't support the idea of Ukraine entering NATO," a Foreign Ministry statement said. 
 
 It added that Kiev must understand that the prospects for future cooperation between Ukraine and Russia, including on economic matters, "will largely depend on the actions Ukraine takes in its foreign policy." 
 
 Russia annexed Ukraine's Crimean Peninsula last month amid the political upheaval that followed the ouster of the pro-Moscow Yanukovych. 
 
 Ukraine's parliament on Tuesday granted permission for foreign military units, including some from NATO countries, to conduct military exercises in Ukraine in 2014. 
 
 Such military exercises by foreign troops, including naval drills in the Black Sea, are an annual event but take on additional significance this year in light of Russia's military takeover of Crimea. 
 
 Gazprom hikes natural gas price 
 
 In a move that will heighten pressure on the interim government in Kiev, Russian energy giant Gazprom announced a sharp increase in the price it charges Ukraine for natural gas. 
 
 Starting Tuesday, Ukraine will be charged $385.50 per 1,000 cubic meters of gas, up from the previous rate of $268.50, Russian state news agency RIA Novosti quoted Gazprom Chief Executive Alexei Miller as saying. 
 
 The move ends a discount that was agreed to before Yanukovych was ousted in February after months of street protests. 
 
 The gas price hike will only increase the pressure on Ukraine's interim government as it seeks to stave off economic collapse. 
 
 Ukraine, which is heavily reliant on Russia for energy, is also $1.7 billion in arrears in its payments for gas already supplied, Miller said, according to RIA Novosti. 
 
 The International Monetary Fund last week agreed to lend Ukraine up to $18 billion over the next two years in return for a package of reforms, including to its energy market. 
 
 Kiev has been running dangerously low on cash to pay for imports and service its debts since the ouster of Yanukovych, which killed off a $15 billion financial lifeline from Russia. 
 
 Is Crimea gone? Annexation no longer the focus of Ukraine crisis 
 
 Opinion: Russia's euphoria over Crimea won't last 
 
 CNN Money: Russia fallout pushes Europe to develop shale gas 
 
 Susannah Palk reported from Brussels, Laura Smith-Spark reported and wrote from London. CNN's Alla Eshchenko, Victoria Butenko, Boriana Milanova, James Frater, Talia Kayali, Jason Hanna and Marie-Louise Gumuchian contributed to this report.
– Tough talk as NATO-Russia relations continue to deteriorate: NATO leaders, who meet in the UK later this week, are planning a "rapid reaction" force that can deploy to Russia's worried Eastern European neighbors within 48 hours, reports the New York Times. The "spearhead" force would have a permanent command center to allow it to respond swiftly to threats, the Globe and Mail notes. "This spearhead ... could include several thousand troops, ready to respond where needed with air, sea, and special-forces support," NATO Secretary-General Anders Fogh Rasmussen told reporters. The NATO summit in Newport, Wales, is especially important because "Russia thought it can change the borders of a sovereign European country by force, and this is happening not very far from NATO's borders," says Estonian Prime Minister Taavi Roivas, calling for fresh plans to ensure all members of the alliance are "equally and strongly protected." Russian defense chiefs, meanwhile, say NATO's actions are "evidence of the desire of US and NATO leaders to continue their policy of aggravating tensions with Russia" and that Moscow plans to craft a new military doctrine in response to NATO plans and the Ukraine crisis, the BBC reports. In Ukraine, President Petro Poroshenko accused Russia of "direct and undisguised aggression" yesterday as government forces continued to suffer reverses, including a retreat from the Luhansk airport, where the Ukrainian military says a Russian tank battalion supported pro-Russia rebels, Reuters reports.