Media playback is unsupported on your device Media caption What does body language tell us about the Trump-Putin G20 meeting? 
 
 Donald Trump and Vladimir Putin have held their first face-to-face talks, on the sidelines of the G20 summit in the German city of Hamburg. 
 
 "It's an honour to be with you," Mr Trump told Mr Putin, who responded: "I'm delighted to meet you personally." 
 
 Both sides listed a wide range of topics discussed, including Russia's alleged meddling in the US election. 
 
 Climate change and trade are set to dominate the two-day G20 meeting. 
 
 Violent clashes between protesters and police have taken place in the streets outside the venue, with dozens left injured. 
 
 A huge police operation is trying to keep demonstrators - who are protesting against the presence of Mr Trump and Mr Putin, climate change and global wealth inequalities - well away from the summit venue, and water cannon have been deployed. 
 
 Earlier, US First Lady Melania Trump was unable to leave her hotel in Hamburg because of the protests. 
 
 "Putin and I have been discussing various things, and I think it's going very well," Mr Trump told reporters while sitting alongside Mr Putin at the start of the talks, which were open to the media. 
 
 "We've had some very, very good talks. We're going to have a talk now and obviously that will continue. We look forward to a lot of very positive things happening for Russia, for the United States and for everybody concerned." 
 
 Mr Putin, via a translator, said that while they had spoken by phone, a phone conversation was never as good as meeting face to face. 
 
 Both men ignored shouted questions from reporters as the meeting went into private session. 
 
 Media playback is unsupported on your device Media caption Police and anti-summit protesters clashed for a second day 
 
 Speaking afterwards, Mr Putin said: "I've had a very long conversation with the US president. We had a lot of issues to discuss, including Ukraine, Syria, and other problems, also some bilateral issues. 
 
 "We have again returned to the fight against terror and to cyber security." 
 
 Secretary of State Rex Tillerson largely confirmed these were the topics covered, saying the leaders connected quickly and had positive chemistry. 
 
 But the two sides seem unable to agree on the exact outcome of talks over the Russian hacking allegations. 
 
 Russian Foreign Minister Sergei Lavrov said Mr Trump accepted Mr Putin's assertions that they were not true. 
 
 Mr Tillerson, meanwhile, said the two men had had a "robust" discussion on the issue during the two hour and 15 minute meeting, and that Mr Trump had pressed the Russian leader on several occasions. 
 
 However, he said it was not clear whether the two countries would ever come to an agreement on what happened. 
 
 "I think the president is rightly focused on how do we move forward from something that may be an intractable disagreement at this point," Mr Tillerson said, according to the Associated Press news agency. 
 
 Mr Tillerson also said they had discussed Syria and its future, and shared "commonalities on what outcome should be", although they had different ideas on how to get there. 
 
 They have, however, agreed to declare a ceasefire in south-west Syria from Sunday, Mr Lavrov said. 
 
 Earlier, a brief video clip posted on the German government's Facebook page showed Mr Trump and Mr Putin meeting for the first time and shaking hands, with Mr Trump patting Mr Putin's arm as they smiled in the company of other leaders. 
 
 Plenty to talk about, by the BBC's Sarah Rainsford 
 
 The words were warm enough, but the body language was restrained as this meeting began. Neither man was smiling much as both said they hoped for positive results from their encounter. Their handshake, when it finally came, was brief and businesslike. 
 
 But they clearly had plenty to talk about, as their meeting went on well over the time allocated. Russia sees that alone as a success, proof that Vladimir Putin is a global leader to be reckoned with. No-one here is expecting any big deals though, like lifting sanctions for example. 
 
 The Kremlin has stressed all along that its main aim is to establish a "working dialogue" with Donald Trump, and perhaps begin the slow process of restoring relations with the US, which are at their lowest point in many years. 
 
 The two men staked out opposing views on major international issues in the run-up to the summit: 
 
 On Thursday, Mr Trump used a speech in the Polish capital Warsaw to call on Russia to stop "destabilising" Ukraine and other countries, and "join the community of responsible nations" 
 
 Setting out his own G20 agenda in German financial newspaper Handelsblatt, Mr Putin called for US-led sanctions on his country, imposed in response to Russia's annexation of Crimea in 2014, to be lifted 
 
 Mr Putin also argued strongly in favour of the Paris climate agreement, saying it was a "secure basis for long-term climate regulation" and Russia wanted to make a "comprehensive contribution to its implementation" 
 
 President Trump has taken the US out of the Paris agreement 
 
 Media playback is unsupported on your device Media caption Mr Trump was once popular in Russia, but opinion there has turned against him since he came into office 
 
 The G20 (Group of Twenty) is a summit for 19 countries, both developed and developing, plus the EU. 
 
 In her summit opening statement, German Chancellor Angela Merkel said: "We are all aware of the great global challenges. 
 
 "We know that time is short and therefore solutions very often can only be found if we are ready to compromise and work together without bending over backwards too much because, of course, we can express different views on some issues." 
 
 Canadian Prime Minister Justin Trudeau has urged G20 leaders to impress upon Mr Trump that he should act as a role model in addressing climate change. 
 
 "We'll tell him it's important to take a lead role in tackling climate change and creating good jobs," he told German tabloid Bild, according to Reuters news agency. 
 
 Mrs Merkel has said the G20 will focus on the Paris climate deal but, as the G20 host, she will work to find compromises. 
 
 Mrs Merkel and other EU leaders have also expressed their commitment to an open international trading system, while the Trump administration pursues protectionism under the "America First" motto. 
 
 On Friday, the US first lady had been due to take part in an excursion with other leaders' spouses, but her spokeswoman Stephanie Grisham said: "The Hamburg police could not give us clearance to leave." 
 
 Mrs Trump herself tweeted concern for those injured in the protests. ||||| FILE PHOTO: Russian President Vladimir Putin attends a news conference at the Kremlin in Moscow, Russia, on January 17, 2017 and U.S. President Donald Trump seen at a reception ceremony in Riyadh, Saudi Arabia, on May 20, 2017, as seen in this combination photo. Sputnik/Alexei Druzhinin/Kremlin via REUTERS and Bandar Algaloud/Courtesy of Saudi Royal Court/Handout/File photos via REUTERS 
 
 HAMBURG U.S. President Donald Trump and Russian President Vladimir Putin, a veteran businessman and a former spy, meet in person for the first time on Friday in the most highly anticipated encounter on the sidelines of the G20 summit. 
 
 Trump has said he wants to find ways to work with Putin, a goal made more difficult by sharp differences over Russia's actions in Syria and Ukraine, and allegations Moscow meddled in the 2016 U.S. presidential election. 
 
 That means every facial expression and physical gesture will be analyzed as much as any words the two leaders utter. The Kremlin said the two enjoyed a passing handshake at the summit ahead of the talks later in the day. 
 
 "I look forward to all meetings today with world leaders, including my meeting with Vladimir Putin. Much to discuss," Trump wrote in a tweet on Friday. "I will represent our country well and fight for its interests!" 
 
 The meeting is scheduled for 3:45 p.m. local time, shortly after a G20 working session on climate and energy begins. 
 
 Trump, who has angered world leaders with his decision to pull the United States out of the Paris accord on climate change, will likely have to leave that session early to make the Russia meeting. 
 
 Some fear the Republican president, a political novice whose team is still developing its Russia policy, will be less prepared for their sit-down than Putin, who has dealt with the last two U.S. presidents and scores of other world leaders. 
 
 "There's nothing ... the Kremlin would like to see more than a (U.S.) president who will settle for a grip and a grin and walk away saying that he had this fabulous meeting with the Kremlin autocrat," Representative Adam Schiff, the top Democrat on the House of Representatives' Intelligence Committee, said in an interview on MSNBC. 
 
 As investigations at home continue into whether there was any collusion between Trump's presidential campaign and Russia, the U.S. president has come under pressure to take a hard line against the Kremlin. 
 
 Moscow has denied any interference and Trump says his campaign did not collude with Russia. 
 
 On Thursday, Trump won praise from at least one Republican hawk in the U.S. Congress after his speech in Warsaw in which he urged Russia to stop its "destabilizing activities" and end its support for Syria and Iran. 
 
 "This is a great start to an important week of American foreign policy," said Republican Senator Lindsey Graham, who has often been critical of Trump on security issues. 
 
 But earlier in the day, Trump declined to say definitively whether he believed U.S. intelligence officials who have said that Russia interfered in the 2016 election. 
 
 "I think it was Russia but I think it was probably other people and/or countries, and I see nothing wrong with that statement. Nobody really knows. Nobody really knows for sure,” Trump said at a news conference, before accusing Democratic former President Barack Obama of not doing enough to tackle hacking. 
 
 SENATORS' CONCERNS 
 
 Ahead of Trump’s meeting with Putin, three U.S. senators wrote to Trump to express “deep concern” about reports that his administration planned to discuss the return to Russia of diplomatic compounds in Maryland and New York that were seized by the Obama administration last year in response to alleged Russian election meddling. 
 
 Republican Senators Johnny Isakson and Marco Rubio and Democratic Senator Jeanne Shaheen said returning the facilities would "embolden" Putin and encourage further efforts by Russia to interfere in Western elections. All three are on the Senate Foreign Relations Committee. 
 
 The White House declined to offer details on what Trump would request of Putin and what he might offer in exchange for cooperation. 
 
 U.S. Secretary of State Rex Tillerson said Trump wanted to talk about how the two countries can work together to stabilize war-ravaged Syria. 
 
 "The United States is prepared to explore the possibility of establishing with Russia joint mechanisms for ensuring stability, including no-fly zones, on-the-ground ceasefire observers, and coordinated delivery of humanitarian assistance," Tillerson said before leaving the United States to join Trump in Germany. 
 
 Trump was also grappling with a response to North Korea's successful test of an intercontinental ballistic missile, which analysts say had a long enough range to reach Alaska. 
 
 Curbing Pyongyang's nuclear ambitions has been Trump's most pressing foreign policy priority, and he met with leaders from Japan and South Korea on Thursday evening to discuss it. He is also slated to meet with Chinese President Xi Jinping at the G20. 
 
 "I’d like to see the president figure out how to engage Russia on North Korea,” said Representative Francis Rooney, a Republican from Florida who is on the House Foreign Affairs Committee. 
 
 "What I suggested to the president here a while back was that since we have all these conflicting issues about Russia right now and we’re still reeling from the fact that they took Crimea, maybe this is an opportunity to reset the Russia relationship in a positive manner,” Rooney said in an interview. 
 
 (Additional reporting by Patricia Zengerle, Susan Heavey and Doina Chiacu in Washington; Editing by Ralph Boulton) ||||| Hamburg, Germany (CNN) All eyes will be on President Donald Trump and Russian President Vladimir Putin on Friday when the two controversial world leaders meet for the first time. 
 
 The official bilateral meeting will bring Trump face-to-face with the leader of the country that United States intelligence says meddled in the 2016 election in an effort to get Trump elected. 
 
 Over the past several days, Trump has been presented with a large binder of preparation materials for his trip to Europe -- but the section on his meeting with Putin amounts to only a "few pages" of paper, according to one White House official. A second official said each talking point is only a sentence or two long to keep Trump focused during his meeting. 
 
 Who will be in the room when Trump meets Putin? 
 
 Who will be in the room when Trump meets Putin? 03:37 
 
 Who will be in the room when Trump meets Putin? 
 
 Behind the scenes, advisers still express concern at Trump's unpredictability ahead of the session with Putin, especially in light of Putin's known practice of preparing extensively for his meetings with US leaders. 
 
 Everything from Trump's body language with Putin to what he decides to say in the brief public portion of the encounter will be dissected the world over. Americans and Russians will watch their world leaders closely, but so will foreign powers who hope to glean information about how the new administration views Russia. 
 
 Here's what to watch for: 
 
 Optics, optics, optics 
 
 It is generally the optics, not the substance, that defines a meeting such as this. 
 
 How will the two leaders present themselves? The body language and demeanor of the short public portion of Trump's meeting with Putin will be analyzed, analyzed again and then over-analyzed for days and weeks. Will they be standing or sitting? Does Trump shake Putin's hand? Does Trump use his height to lord over Putin? Or does Putin stay stoic and distant? 
 
 Trump has grown more aware of the optics that come with a bilateral meeting since his first visit with British Prime Minister Theresa May at the White House in January, where the president famously held May's hand while walking. Months later, Trump failed to shake German Chancellor Angela Merkel's hand during their meeting in the Oval Office, cementing the global view that their relationship was icy. 
 
 JUST WATCHED Trump, Merkel begin visit with handshake Replay More Videos ... MUST WATCH Trump, Merkel begin visit with handshake 00:45 
 
 Trump was far chummier in May when he met with Russia's Foreign Minister Sergei Lavrov and Ambassador to the US, Sergey Kislyak, at Putin's request. Photos of the encounter showed Trump laughing, pointing to Kislyak and slapping Lavrov on the back. Later it came out that Trump revealed highly classified information during the meeting. But the optics of the encounter already cemented the public view of Trump's relationship with Russia: friendly. 
 
 What do they talk about? 
 
 Cameras -- not surprisingly -- won't be allowed for the entirety of Trump's meeting with Putin, so the substance of what the two will discuss will be left to official readouts from each government and leaks from those in the room. 
 
 But the key question going into the meeting is whether Trump will bring up Russia's election meddling. 
 
 Trump, administration officials tell CNN, plans to focus primarily on disputes in Syria and Ukraine when he meets with Putin on Friday. While a formal plan for the meeting has yet to emerge, there is little expectation on the American side that Trump will bring up Russia's 2016 activities. 
 
 JUST WATCHED Will Trump bring up election meddling in Putin meeting? Replay More Videos ... MUST WATCH Will Trump bring up election meddling in Putin meeting? 08:06 
 
 The President said Thursday that Russia could have been behind efforts to influence the election but suggested the finger can be pointed elsewhere as well and that "nobody really knows for sure." 
 
 "I think it very well could be Russia but I think it could very well have been other countries," Trump said during a news conference with Polish President Andrzej Duda . Russia has denied any involvement. 
 
 The Russians have looked to tamp down any suggestion that Trump and Putin will dive deeply into Russia's incursions into Ukraine. Kremlin spokesman Dmitry Peskov told reporters on Wednesday that the meeting will "inevitably be limited in time" and therefore there will likely not be enough time for Putin to present "the full understanding" of the situation in Ukraine. 
 
 Is Trump-Putin an Obama-Putin redux? 
 
 Former President Barack Obama's relationship with Putin was contentious. 
 
 "The personal relationship is very bad," Matthew Rojansky, a director at The Wilson Center told NPR in 2013. "There's no sugarcoating that, even though both have tried." 
 
 The crescendo of their contentious relationship came in September 2016, when the two shared a visibly terse meeting on the sidelines of the G20 in Hanghzhou, China. Photos of the meeting showed a stern Obama staring down Putin. 
 
 Russian President Vladimir Putin meets with his US counterpart Barack Obama on the sidelines of the G20 Leaders Summit in Hangzhou on September 5. 
 
 Obama later revealed that he told Putin "to cut it out" in his meddling in the 2016 election or "there were going to be serious consequences if he did not." 
 
 Not all presidents have viewed Putin with such skepticism, so a warm relationship with Trump would not be abnormal. 
 
 President George W. Bush said during a 2001 meeting with Putin that he was able to look him in the eye and "get a sense of his soul." 
 
 "I looked the man in the eye. I found him to be very straightforward and trustworthy," Bush said, standing next to Putin. "We had a very good dialogue. I was able to get a sense of his soul, a man deeply committed to his country and the best interests of his country. And I appreciated so very much the frank dialogue." 
 
 He later added, "I wouldn't have invited him to my ranch if I didn't trust him." 
 
 Does North Korea's missile test change the Putin-Trump meeting? 
 
 Trump has taken a hardline stance against North Korea since he took office in January, but the rogue regime has ratcheted up, not calmed down, its missile tests. Most recently the North Koreans tests what they claimed was an intercontinental ballistic missile on July 4 
 
 So far, Trump's ire with the Kim Jong Un-led country has been focused on China. 
 
 "Trade between China and North Korea grew almost 40% in the first quarter," he tweeted hours before leaving for Poland. "So much for China working with us - but we had to give it a try!" 
 
 Trade between China and North Korea grew almost 40% in the first quarter. So much for China working with us - but we had to give it a try! — Donald J. Trump (@realDonaldTrump) July 5, 2017 
 
 But Russia, like China, shares a border with North Korea and has so far defended the regime in the face of condemnation from the United States. 
 
 Lavrov warned Wednesday that Russia and China consider "unacceptable" any attempts to "justify a military solution" for the Korean peninsula by using the UN Security Council as an excuse. 
 
 "Any attempts of economic suffocation of the DPRK are also unacceptable," Lavrov added. 
 
 With North Korea's actions threatening to overshadow the G20 meeting, if Trump mentions North Korea in his meeting with Putin -- and how he does so -- may well prove key to future American actions on the regime. 
 
 How much does Trump's visit to Poland impact his Putin meeting? 
 
 Trump gave a well-received speech Thursday in Poland, a country whose fear and distrust of Russia is fundamental to its existence and its membership in the North Atlantic Treaty Organization, which the country joined in 1999. 
 
 And he strongly backed Article 5, the principle that dictates an attack against one NATO country is an attack against all of NATO. 
 
 "To those who would criticize our tough stance, I would point out that the United States has demonstrated not merely with words but with its actions that we stand firmly behind Article 5, the mutual defense commitment," Trump said. 
 
 Trump failed to mention Article 5 during his first trip to Brussels in May, causing some to question his commitment to the principle. The White House dismissed those questions, arguing Trump's presence at an event honoring Article 5 and NATO's role in responding to the September 11 terrorist attacks was enough clarity about the United States' commitment to NATO collective defense. 
 
 Putin and Russia remain deeply skeptical of NATO. In June, Putin threatened to "eliminate" the "threat" of Sweden joining NATO. 
 
 "If Sweden joins NATO this will affect our relations in a negative way because we will consider that the infrastructure of the military bloc now approaches us from the Swedish side," Putin told his state news agency. "We will interpret that as an additional threat for Russia and we will think about how to eliminate this threat."
– For the first time since becoming POTUS, Donald Trump has met Russian President Vladimir Putin. The meeting happened on the sidelines of what Reuters calls a "closely watched" G20 summit. They're not kidding, considering the first media coverage coming out of the summit focuses on the handshake between the two, which was of course caught on video. Reuters notes that in addition to the handshake, Trump patted Putin on the arm and later on the back, and both men smiled. Per the Guardian, Trump told Putin, "Mr. Putin, it is an honor to be with you." Putin's reply: "I’m delighted to meet you personally, and I hope our meeting will bring results." The moment took place at an informal meeting of G20 leaders as the summit began in Hamburg, Germany; Trump and Putin are to hold their formal meeting at 3:45pm local time. Read why the meeting could be a "win-win" for Putin here.