
President Donald Trump and Russian President Vladimir Putin sat down for their much-anticipated first meeting on Friday on the sidelines of the G20 summit.

The two exchanged brief pleasantries and a friendly handshake earlier at the start of the summit in Hamburg, Germany, but waited hours before they could speak privately.

As their meeting kicked off, Trump said 'It's an honor to be with you', while Putin told the US leader: 'I'm delighted to meet you.'

Trump said he anticipates 'a lot of positive things happening, for Russia, for the United States', adding that their talks on 'various things' were 'going very, very well'.

Their first sit-down meeting is expected to last for about 30 minutes and touch upon several complex issues, from the Syrian conflict to Russia's provocations in Ukraine.

President Donald Trump said that he was 'honored' to meet Russian President Vladimir Putin as they sat down together on Friday afternoon. Putin responded by saying he was 'delighted' to meet the president. As the meeting started he said that he and Putin had been 'discussing various things and I think it's going very, very well'

The pair spoke briefly to the press before starting their meeting, and Trump said that he was looking forward to some 'positive talks' with Putin

However, the meeting also falls under the shadow of accusations that Russia meddled in the 2016 presidential election - and Trump is under pressure to raise those concerns with Putin in their first meeting.

Trump, on Thursday, said he believes Russia may have interfered in the election, but he said that he believes other countries may have been involved as well.

His and Putin's first handshake was captured on film in a video that shows the hidden handshakes and back-slaps between political leaders at the summit.

Their surprising gesture was more familiar than anything else shown on the 40-second video clip, which was first published on Facebook.

When Putin greets UK Prime Minister Theresa May, for instance, the handshake is formal, curt and respectful – with the leaders bowing to each other slightly.

President Donald Trump and Russian President Vladimir Putin gave one another a warm welcome on Thursday as they shook hands during their introduction at the G20 Summit in Hamburg, Germany

In video of the meeting, Trump is seen shaking Vlad's hand rightie-to-rightie, and using his left hand to pat the underside of Putin's arm

The pair smiled and told one another they would see each other soon in a private meeting. Trump earlier tweeted that he had 'much to discuss' with the Russian leader

At one point during their brief initial meeting, Putin pointed at Trump as they continued to shake hands. Their private meeting is scheduled for later on Friday

UK Prime Minister Theresa May and EU institutional chiefs Jean-Claude Juncker and Donald Tusk were nearby when Trump and Putin greeted one another. Trump is pictured rubbing the Russian leader's back

The promise of a fresh start to US-Russia relations has been eclipsed by allegations of collusion between the Kremlin and members of Trump's election campaign team

Trump watches Putin as he speaks to President of the European Commission Jean-Claude Juncker at the G20 summit on Friday

But when Trump comes up to the same table to see Putin, the how-do-you-do is more congenial – the stuff of fishing buddies or bowling teammates.

In a later clip, Trump is shown extending his left arm to pat Putin's back while he smiles broadly.

Until Thursday, the two men had reportedly never met.

Trump is trying to establish a rapport with Putin, one White House aide said Friday, in the hope that the two men can reach a detente and avoid a new Cold War.

But the US president's critics warn that Putin, a former KGB spymaster, is a master of manipulation who can meet every Trump volley with an overhand smash.

The footage was shot during the leaders' 'retreat' – an informal gathering before the more consequential meetings that form the basis of G20 policy discussions.

German Chancellor Angela Merkel takes part in a family photo along with French President Emmanuel Macron, U.S.President Donald Trump, Indonesia's President Joko Widodo, Mexico's President Enrique Pena Nieto, South African President Jacob Zuma, Argentina's President Mauricio Macri, Chinese President Xi Jinping, Russian President Vladimir Putin, Turkish President Recep Tayyip Erdogan, Brazilian President Michel Temer, South Korea's President Moon Jae-in, Italian Prime Minister Paolo Gentiloni, Canadian Prime Minister Justin Trudeau, India's Prime Minister Narendra Modi, Japanese Prime Minister Shinzo Abe, Australian Prime Minister Malcolm Turnbull, Britain's Prime Minister Theresa May, European Council President Donald Tusk, European Commission Jean-Claude Juncker, U.N. Secretary-general Antonio Guterres, Norway's Prime Minister Erna Solberg, Netherlands' Prime Minister Mark Rutte, Senegal's President Macky Sall, Singapore's Prime Minister Lee Hsien Loong, Spanish Prime Minister Mariano

Trump (second from left in the front row) and Putin (fourth from right in the front row) stood far from another in a group shot of the leaders involved in the G20 summit

After the photo was take, Macron and Trump chatted as Trudeau and Pena Nieto stood by. Throughout the weekend, the group will discuss climate change and global trade

Merkel covers her face as she speaks to Trump at the start of the G20 on Friday. US Secretary of the Treasury Steve Mnuchin (back right) was also at the event

Putin listens to Merkel as she appears to reference someone's height during the first working session of the G20

Mediator Merkel? The German Chancellor listens in as Macron and Trump exchange a few words

Merkel, Trump and Macron talk before getting down to business at the start of the first working session of the G20 meeting

Macron and Trump laughed as they stood next to one another during a posed group photo of all of the world leaders at the G20 Summit

Merkel told leaders of the Group of 20 economic powers Friday that millions of people are hoping they can help solve the world's problems, and warned them that they must be prepared to make compromises. Pictured above, Trump and Macron at the event

Before Putin, Trump tried to manage another rocky international relationship as he with Mexican President Enrique Pena Nieto. Pena Nieto insists Mexico will not pay. Trump hailed Pena Nieto as a 'friend' in their face-to-face meeting on Friday, but said he 'absolutely' wants Mexico to pay for the wall

Pena Nieto had been scheduled to visit the White House shortly after Trump took office, but he scrapped the trip at the last minute due to disagreement with Trump over the US president's insistence that Mexico pay for the wall he has vowed to build along the US-Mexico border to deter illegal immigration

From left to right, Trump, China's President Xi Jinping, Merkel, Argentinia's President Mauricio Macri and Australia's Prime Minister Malcolm Turnbull turn around for photographers at the start of the first working session of the G20 meeting

British Prime Minister Theresa May, US President Donald Trump, Chinese President Xi Jinping and German Chancellor Angela Merkel smile for the cameras

Macron (center right) talks to Merkel (center left, back to camera) as Trump (right) looks on during the opening session of the G20

Trump talks to the President of Turkey Recep Tayyip Erdogan (right) and others before the beginning of first working session of the G20 Nations Summit

Merkel (center) talks to European Commission President Jean-Claude Juncker (left) as European Council President Donald Tusk (R) listens during the opening session of the G20 summit

Trump speaks to Macron and Merkel ahead of the start of the Summit. Trump will be visiting Paris next week in honor of Bastille Day

Trump and his colleagues will remain in Hamburg until Saturday. He earlier tweeted that he had 'much to discuss' with the Russian leader.

'I look forward to all meetings today with world leaders, including my meeting with Vladimir Putin. Much to discuss,' Trump wrote, adding the hashtag #USA and an American flag emoji.

Friday's much-anticipated encounter in Hamburg, Germany, comes at a pivotal time in US-Russian relations. Trump will be closely watched to see if he confronts Putin over Russia's meddling in the 2016 presidential election.

Ahead of the G20 Summit's start, Trump vowed to fight for US interests, despite the 'Fake News Media' he claims covers him inaccurately.

'I will represent our country well and fight for its interests! Fake News Media will never cover me accurately but who cares! We will #MAGA!' he Tweeted ahead of the G20 Summit, where he will meet with world leaders.

Trump sat next to Britain's Prime Minister Theresa May as they prepped to start the first working session of the G20 meeting

From left to right, President of Brazil Michel Temer, Prime Minister of Australia Malcolm Turnbull, President of Argentina Mauricio Macri, German chancellor Angela Merkel, Chinese President Xi Jinping, US President Donald J. Trump and British Prime Minister Theresa May during the plenary session of the G20 Summit in Hamburg

Merkel, sitting in the center of the room in red, spoke to the group of world leaders at the plenary session of the G20 Summit

Trump sits alone at the beginning of the plenary session of the G20 Summit as others involved in the talks take their seats

China's President Xi Jinping and Trump begin listening into the discussion on the first day of the G20

Trump (center) smiles towards Turkish President Recep Tayyip Erdogan (second right, back to camera) while Chinese President Xi Jinping (left) takes his seat

May (left) chats with Turkish President Recep Tayip Erdogan (second right) and Turkish Foreign Minister Mevlut Cavusoglu (second left) at the beginning of the plenary session

South Africa's President Jacob Zuma, Russia's President Vladimir Putin and Mexico's President Enrique Pena Nieto talk at the start of the 'retreat meeting'

Merkel talks to Russia's President Vladimir Putin at the start of the first working session of the G20 meeting in Hamburg

Merkel gets comfortable as she begins her bilateral meeting with Prime Minister Justin Trudeau at the G20 summit on Friday

The president arrived Friday morning after most of his international counterparts, shaking hands with German Chancellor Angela Merkel with a friendly 'How are you?' greeting.

Merkel, as the host leader, greeted every head of state personally on a red carpet as camera shutters clicked.

She got kisses on the cheek from European Commission President Jean-Claude Juncker, European Council President Donald Tusk, Italian Prime Minister Paolo Gentiloni, Canadian Prime Minister Justin Trudeau and French President Emmanuel Macron.

After 15 leaders had arrived, an announcer said the welcome proceedings were over. Merkel exited but came back several minutes later to greet Trump, South Korean President Moon Jae-in and Chinese President Xi Jinping.

Trump clasped Merkel on the shoulder as they both disappeared inside the G20 meeting room.

During a brief photo call at the top of the leaders' retreat, Trump was seated between Merkel and UK Prime Minister Theresa May.

While May chatted with the US president, Merkel faced away from them and chatted with Macron.

PROTESTERS CLASH WITH POLICE AS G20 GETS UNDERWAY IN HAMBURG A police station has been firebombed and cars and buildings set alight in the German city of Hamburg, where world leaders are holding crunch talks today. Police have called for reinforcements after tens of thousands of protesters descended on Hamburg, causing chaos. Shocking footage shows smoke billowing from vehicles as the city hosting the G20 summit looked like a warzone. German police confirmed this morning that the police station had been targeted by 'perpetrators of violence', as thousands of officers flood the streets anticipating violent demonstrations. Hamburg police say they have used a water cannon to clear a blockade by protesters ahead of the opening of the Group of 20 summit Police said the incident happened on the banks of the Outer Alster lake, some distance from the trade fair grounds where the summit is being held, on Friday morning. They said they had repeatedly told a group of protesters to clear the road Officers repeatedly used water cannons, as well as pepper spray and batons, on Thursday evening amid clashes with violent protesters It comes after more than 70 people were injured in clashes between riot police and anti-capitalists last night, with a march named 'Welcome to Hell' descending into chaos. This morning Hamburg police used a water cannon to clear a blockade by protesters ahead of the opening of the summit. A spokeswoman for the US First Lady told DPA: 'We have not received the all-clear from police to leave the residence.' Other spouses including Theresa May's husband Philip and French president Emmanuel Macron's wife Brigette have also been told to stay indoors. A visit to a climate change centre by G20 spouses has been cancelled, DPA reports. Hamburg police, who are already being backed up by officers from other German states as well as from Austria, made the request for reinforcements 'in order to get relief', a spokesman said. The meeting opens after skirmishes Thursday evening between police and violent protesters elsewhere in the port city, Germany's second-biggest. Police said that at least 76 officers were hurt, one of whom had to be taken to a hospital with an eye injury after a firework exploded in front of him Protesters clash with German police dressed in full swat gaer during the start of the G-20 summit in Hamburg on Friday A female protester is detained by several German police officer during demonstrations in Hamburg during the G20 Summit Police push away activists who tried to block a street during the G20 summit in Hamburg on Friday, an event gathering leaders from around the world Police said the blockade happened on the banks of the Outer Alster lake, some distance from the trade fair grounds where the summit is being held. They said they had repeatedly told a group of protesters to clear the road. Officers repeatedly used water cannons, as well as pepper spray and batons, on Thursday evening amid clashes with violent protesters. Up to 100,000 anti-capitalist protesters are expected to descend on the city today, as heads of state including US President Donald Trump and Russian leader Vladimir Putin meet for the G20 talks. Police said that at least 111 officers were hurt during yesterday's clashes, one of whom had to be taken to a hospital with an eye injury after a firework exploded in front of him. Twenty-nine people were arrested and a further 15 temporarily detained. Organiser Andreas Blechschmidt criticised what he said was a heavy-handed and 'massive' police response with batons. 'The police should have reacted proportionally... It wasn't necessary. There are a lot of people injured,' Blechschmidt said on N-TV. Around 30 people were arrested. Demonstrators use concrete blocks to barricade the road near Schlump station on the opening day of the G20 summit in Hamburg Demonstrators use concrete blocks to barricade the road near Schlump station on the opening day of the G20 summit in Hamburg 'War, climate change, exploitation are the result of the capitalist system that the G20 stands for and which 20,000 police are here to defend,' demonstrator Georg Ismail told AFP. Burned out cars today bear testimony to the violence ahead of the talks. Police believe as many as 8,000 protesters are ready to commit violence. More than 70 people were injured in last night's clashes. Officers say they repeatedly asked a group of demonstrators to remove their masks and hoods last night, but instead officers were hit with bottles and bricks - breaking the window of a riot van. They then decided to separate the group from the rest of the march, which they estimated at 12,000 people in total. The violence broke out near the start of the demonstration at a riverside plaza used for Hamburg's weekly fish market. As leaders arrived yesterday, riot police fired water cannon at a group of about a thousand black-clad protesters who hurled bottles in a demonstration organisers had dubbed 'Welcome to Hell'. Some 20,000 police from all of Germany's 16 states have been deployed on the streets of Hamburg. Advertisement

The room, a cavernous sea of bright yellow carpet, put at least 50 feet of distance between Trump and Putin, who was seated a quarter of the way around the giant circle.

But the two men did meet and shake hands and greeted each other warmly.

'They shook each other's hand and said that they would soon hold a separate meeting, would soon see each other,' Kremlin spokesman Dmitry Peskov told a conference call with reporters.

When asked if Putin was looking forward to the talks and whether he had lots of questions for Trump, Peskov said he did.

US lawmakers and federal investigators are continuing to look into Russia's election interference, along with possible collusion between Trump campaign associates and Russian government officials.

Russia has been accused by four US intelligence agencies of interfering in the national election that hoisted Trump to power last year.

That puts Trump under intense scrutiny over how he handles the sit-down with Putin, a former Russian intelligence agent known to come well-prepared to meetings like this.

President Donald Trump and Russian President Vladimir Putin were greeted by German Chancellor Angela Merkel ahead of the the G20 summit on Friday

Ahead of the meeting, Trump vowed to fight for US interests, despite the 'Fake News Media' he claims covers him inaccurately

The president arrived Friday morning after most of his international counterparts, shaking hands with Merkel with a friendly 'How are you?' greeting

German Chancellor Angela Merkel welcomes Russia's President Vladimir Putin as he arrives to attend the G20 summit in Hamburg

Merkel and Putin laughed as they shook hands at the start of the G20 Summit on Friday morning. The G20 meetings will last two days

During a brief photo call at the top of the leaders' retreat, Trump was seated next to Merkel as all of the leaders said in circular formation

Trump chatted with UK Prime Minister Theresa May as Merkel faced away from them and spoke with French President Emmanuel Macron

Putin attends a BRICS leaders' meeting as he takes part in the G20 summit in Hamburg ahead of his meeting with Trump on Friday

Putin laughed as he spoke with Mexico's President Enrique Pena Nieto as South African President Jacob Zuma sits nearby during a talk at the G20 Summit

Putin and Pena Nieto lean across their chairs to talk at the start of the 'retreat meeting' on the first day of the G20 summit in Hamburg

Trump said at a news conference in Poland on Thursday that Russia 'could have' interfered in the 2016 presidential campaign, but he's not convinced that it was the sole meddler.

'I think it was Russia, and it could have been other people in other countries,' Trump said. 'Nobody really knows.'

He added that the US Intelligence Community has made high-profile mistakes in the past, so 'nobody really knows for sure.'

Trump sought to redirect any scrutiny toward his predecessor, Barack Obama, accusing him of allowing Moscow to meddle on his watch.

Though the Obama administration warned Russia publicly and privately before Election Day to stop interfering, questions have since been raised about whether the office holder acted aggressively enough to stop the threat.

'They say he choked. Well, I don't think he choked,' Trump said. 'I think he thought Hillary Clinton was going to win the election, and he said, 'Let's not do anything about it'.'

Trump said the CIA had informed Obama about the hacking months before the election but added that 'mistakes have been made.'

In Putin, Trump sees a potential ally in the war on radicalism in the Middle East.

Trump was welcomed with a handshake from German Chancellor Angela Merkel, the summit host, as he arrived at the Summit

Trump tweeted ahead of the summit that he's looking forward to his first meeting with Putin at an international summit in Hamburg, Germany

Leaders of the world's rich and developing nation are discussing a variety of issues over two days of meetings at the G20 Summit, including trade and climate change

President Donald Trump is tweeting that 'everyone' in Hamburg, Germany is talking about the Democrats' response to Russian election hacking ahead of his highly-anticipated meeting with Russian President Vladimir Putin

Trump has two big meetings on his schedule apart from the formal summit agenda. He'll meet for the first time as president with Russian President Vladimir Putin and will also hold talks with Mexican President Enrique Pena Nieto

On Thursday, Trump again refused to accept the conclusion by multiple US intelligence agencies that Russia interfered to try to help Trump win last November

Trump's motorcade on Friday was decorated with American and German flags ahead of the G20 summit in Hamburg

President of France Emmanuel Macron arrived at the summit alongside his wife, Brigitte Trogneux. They were welcomed by the of Hamburg, Olaf Scholz

THERESA MAY'S HUSBAND JOINS G20 SPOUSES INCLUDING FRENCH PRESIDENT EMMANUEL MACRON'S WIFE FOR A BOAT TOUR OF HAMBURG Theresa May's husband Philip joined the world leaders' consorts club today as he mingled with spouses of some of the most powerful people on earth. Mr May, 59, was in glamorous company in Hamburg, Germany, as he made his first overseas foray in the role. Among those who joined him for a riverboat cruise this morning were French President Emmanuel Macron's wife Brigitte and Sophie Gregoire-Trudeau, the wife of Canadian Prime Minister Justin Trudeau. By convention, a separate programme of events is organised to entertain wives, girlfriends and husbands who attend major summits. Theresa May's husband Philip joined the world leaders' consorts club today as he mingled with spouses of some of the most powerful people on earth. He is pictured (right) in Hamburg today next to Thobeka Madiba Zuma (left), wife of South Africa's President Jacob Zuma Among those who joined him for a riverboat cruise today were French President Emmanuel Macron's wife Brigitte (left, with Juliana Awada, wife of Argentinian President Mauricio Macri) Sophie Gregoire-Trudeau, wife of Canada's Prime Minister Justin Trudeau, and their son Hadrien leave a ship after a boat tour of the spouses programme on the first day of the G-20 summit in Hamburg, northern Germany The pictures emerged as it was reported that US First Lady Melania Trump and other spouses had been trapped inside their hotel rooms this afternoon amid fierce protests in the city. Their visit to a climate change centre has been cancelled, DPA reports. Mr May will spend much of the next two days in the company of Joachim Sauer, Angela Merkel's husband, who will host the consorts on her behalf. Mr Sauer, a theoretical chemist who grew up in communist East Germany, is normally a low-profile figure. He has organised a 'climate change-themed' programme for those attending. Mr May, who is likely to be the only husband in attendance, was due to join the leaders' wives on a river boat cruise before visiting a climate change centre in the German city. Brigitte Macron, wife of France's President Emmanuel Macron, left, and Juliana Awada, wife of Argentine President Mauricio Macri, disembark from a riverboat after a tour of the city Angelica Rivera (left), partner of Mexico's President Enrique Pena Nieto, and her daughter Regina Castro (right) leave the boat 'Diplomat' on the river Elbe as they take part in the G20 Summit Spouse Programme in Hamburg, Germany He is the first British consort to attend a major summit since Sarah Brown. Samantha Cameron disliked that side of her role and never travelled with her husband to a summit. On Tuesday it emerged that Sauer, who usually shuns publicity, would take the visiting dignitaries sightseeing and to the spectacular new Elbphilharmonie concert house. The leaders' spouses were also due to take in views of Germany's 'Gateway to the World' city on a cruise tour of the country's biggest port, in whose harbour-front bars the Beatles started their rise to fame. The G20 spouses' tour also includes Hamburg's neo-Renaissance town hall, an imposing building dating from the late 1800s, which boasts almost as many rooms as Britain's Buckingham Palace. On Friday evening, the spouses are to be treated to Beethoven's 'Ode to Joy', the EU's anthem, at Hamburg's new Elbphilharmonie, whose glass structure is meant to evoke frozen waves, and which offers sweeping views of Germany's second largest city. Iriana Joko Widodo (left, in red), wife of Indonesia's President Joko Widodo, and Emine Erdogan (left, in purple), wife of Turkish President Recep Tayyip Erdogan were among those who joined the tour. Also in attendance was Akie Abe, wife of Japan's Prime Minister Shinzō Abe Peng Liyuan, wife of Chinese President Xi Jinping, also travelled to Hamburg as her husband joined G20 leaders Advertisement

The Republican president and his administration have held off on slapping Moscow with new sanctions as they assess Putin's willingness to work with the US to defeat ISIS and remove Bashar al-Assad from power in Syria.

Experts on Putin have said it is Trump who should be worried that the Russian president will try to earn concessions.

Putin, like other world leaders who have Trump's number, is most likely to get what he wants by flattering him.

'I would be surprised if Vladimir Putin offers any concessions in exchange for restoring what Russia sees as its inalienable rights,' Dmitri Trenin, director of the Carnegie Moscow Center, told the Associated Press.

'If no agreement is reached, Russia will take retaliatory measures, which could trigger new U.S. moves,' he added.

Trump's deal-making skills and his electoral victory are especially ripe for the complimenting, foreign leaders have found, although Putin is less likely to bring up the latter than other people in positions of power who have sat across from the billionaire.

German chancellor Angela Merkel, right, welcomes Canada's Prime Minister Justin Trudeau at the G-20 summit in Hamburg

Trudeau told a German newspaper on Friday the leaders of G20 countries meeting in Hamburg would tell US President Donald Trump he should take the lead in addressing climate change

German Chancellor Angela Merkel and French President Emmanuel Macron greet each other the G20 summit in Hamburg on Friday

Macron said on Thursday, a day before the start of the G20 Summit, that he supported a two-state solution to end the Middle East conflict

German chancellor Angela Merkel , right, welcomes Britain's Prime Minster Theresa May, at the G-20 summit in Hamburg

May will call on world leaders to choke off funding for terrorists which is being funnelled through the international financial institutions as the G20 meets in Germany

May, who has previously said Britain was disappointed by Trump's decision last month to withdraw the United States from the global agreement, is due to hold a bilateral meeting with Trump on the sidelines of the G20 summit

A close ally of Syria and Iran, Trump called on Russia from Poland to cease its 'destabilizing activities in Ukraine and elsewhere and its support for hostile regimes' in his most forceful remarks on the subject yet during a Thursday speech.

Russia must choose to join the US and its allies in their 'fight against common enemies and in defense of civilization itself,' Trump said.

Putin's government is presently aligned with 'powers that seek to test our will, undermine our confidence, and challenge our interests,' Trump stated.

'To meet new forms of aggression, including propaganda, financial crimes, and cyberwarfare, we must adapt our alliance to compete effectively in new ways and on all new battlefields,' he declared.

Russia has made no indications that it would be willing to sell out Assad in order to take out ISIS. To the contrary, it has continued to work with the ruling class in the face of vicious assaults on women and children.

Trump's attitude coming into office had been to let the civil war in Syria resolve itself. A chemical weapons attack in April that killed 89 changed his mind.

Merkel greets South Korea's President Moon Jae-in as he arrives for the G20 leaders summit. Ahead of the summit, Moon met with Trump and Japanese Prime Minister Shinzo Abe to discuss North Korea

Turkish President Recep Tayyip Erdogan, who earlier in the day had breakfast with Merkel, greets the German chancellor at the start of the G20 summit

Spain's Prime Minister Mariano Rajoy, left, greets Merkel at the summit. Rajoy on Wednesday described as 'authoritarian delirium' plans by the ruling parties in the northeastern Catalonia region to declare independence from Spain within 48 hours of a promised referendum October 1, if voters say 'yes'

Merkel greets Mexico's President Enrique Pena Nieto at the beginning of the G20 summit. Pena Nieto will meet with Trump later during the two-day event

Merkel welcomes India's Prime Minister Narendra Modi at the G20 leaders summit in Hamburg. Modi earlier this week visited Israel, the first-ever by an Indian prime minister

Merkel officially welcomes Japan Prime Minister, Shinzo Abe, to the opening day of the G20 summit. Japan and the European Union agreed a free trade pact on Thursday to create the world's biggest open economic area and signal resistance to what they see as Trump's protectionist turn

Chinese President Xi Jinping, left, is welcomed by Merkel at the summit, where he will also have meetings with President Trump

'These heinous actions by the Assad regime cannot be tolerated. The United States stands with our allies across the globe to condemn this horrific attack and all other horrific attacks, for that matter,' he said during a news conference the following day.

As Trump dropped bombs on the facility in Syria where the attack was launched from several days later he urged 'all civilized nations' to join the US 'in seeking to end the slaughter and bloodshed in Syria, and also to end terrorism of all kinds and all types.'

Before Putin, Trump tried to manage another rocky international relationship as he with Mexican President Enrique Pena Nieto.

Pena Nieto had been scheduled to visit the White House shortly after Trump took office, but he scrapped the trip at the last minute due to disagreement with Trump over the US president's insistence that Mexico pay for the wall he has vowed to build along the US-Mexico border to deter illegal immigration. Pena Nieto insists Mexico will not pay.

Trump hailed Pena Nieto as a 'friend' in their face-to-face meeting on Friday, but said he 'absolutely' wants Mexico to pay for the wall.

Pena Nieto insists Mexico will not pay for the wall.

Saudi Arabia's State Minister Ibrahim al-Assaf, left, is welcomed by Merkel on Friday. Saudi Arabia's King Salman isn't attending the event

Merkel, right, welcomes Italy's Prime Minister Paolo Gentiloni, at the G-20 summit. Gentiloni spoke to Trump in a phone call ahead of the event

Merkel (R) officially welcomes South African President Jacob Zuma (L) on the opening day of the G20 summit in Hamburg

Brazil's President Michel Temer is welcomed by Merkel as he arrives for the G20 leaders summit. Earlier this week, Temer had to present his legal defense against corruption allegations, a move seen as a bid to reduce the likelihood of being suspended from office and tried at the Supreme Court

Merkel officially welcomes Argentinan President Mauricio Macri to the G20 summit. Last month, Macri boosted public spending ahead of a crucial mid-term election

Merkel welcomes the president of the European council, Donald Tusk at the G-20 summit in Hamburg on Friday. Tusk held a joint press conference with Japan's Abe and fellow EU institutional chief Jean-Claude Juncker before the event

Merkel officially welcomes President of the European Commission, Jean-Claude Juncker (left) to the opening day of the G20 summit in Hamburg

Trump said, 'it's great to be with my friend the president of Mexico'. Pena Nieto said he hopes to continue a 'flowing dialogue'.

He reassured Pena Nieto in April that he would not pull out of the North American Free Trade Agreement, which involves the United States, Mexico and Canada.

But Trump said he could still withdraw if he concludes that a renegotiated pact would not produce 'a fair deal' for all sides.

The Putin meeting is the highlight of a hectic, four-day European visit for Trump, who addressed thousands of Poles in an outdoor speech in Warsaw, Poland, on Thursday.

He met in Germany with Chancellor Angela Merkel, the summit host, and had dinner with two Asian allies - Japanese Prime Minister Shinzo Abe and South Korean President Moon Jae-in - to discuss North Korea's aggression.

The Group of 20 gathering of the world's leading rich and developing nations is the first since Trump announced that the United States would withdraw from the Paris climate agreement, deeply disappointing Merkel and other US allies who had hoped to maintain momentum in battling climate change.

Even as Trump has said in vague terms he would like to renegotiate the Paris accord, European leaders have vowed to press forward.