HAMBURG, Germany — President Trump and Russia's Vladimir Putin had their first opportunity to size each other up Friday ahead of their first one-on-one meeting at an international summit in Germany.

The two leaders shook hands and exchanged a few words ahead of their sit-down at the Group of 20 talks in Hamburg, according to Putin’s spokesman Dmitry Peskov. It was the first time the two leaders pressed the flesh since U.S. intelligence agencies accused Putin of interfering in last year's presidential election to get Trump elected.

Earlier Friday, Trump tweeted: "I look forward to all meetings today with world leaders, including my meeting with Vladimir Putin. Much to discuss."

Trump also brought up Russia's meddling in the 2016 presidential campaign

"Everyone here is talking about why John Podesta refused to give the DNC server to the FBI and the CIA. Disgraceful!," he said, an apparent reference to the phishing scam that led to an email leak from the Democratic National Committee.

In their first formal meeting later Friday, the two presidents are expected to discuss the Syrian war, the crisis in Ukraine and the fight against extremism and terrorism.

In the opening session of the summit, Trump sat next to German Chancellor Angela Merkel and British Prime Minister Theresa May.

Anti-globalization activists in Germany's second largest city set dozens of cars ablaze and tried to block leaders’ delegations, including first lady Melania Trump, from entering the grounds of the summit. Overnight, dozens of police were injured.