Late night hosts Jimmy Fallon and Stephen Colbert accuse Trump of 'treason' after Putin meeting

Late night TV hosts and other celebrities have reacted to US President Donald Trump's meeting with Vladimir Putin on Monday.

TV stars including Jimmy Fallon, Stephen Colbert and Seth Meyers were among those to react after the summit. Meyers accused Trump of "selling out our democracy" in a "Closer Look" segment devoted to the "surreal" goings on in Helsinki.

He ran through a series of clips from the press conference where a "thirsty" Trump rambled about Hillary Clinton's emails, the Democrats, the lack of collusion and Putin's "strong and powerful denial" over Russian interference in the US election.

"[He] gushes over Putin like a flustered 12-year-old who just met Mickey at Disneyland," Meyers said.

"It's only a matter of weeks before he Single White Female's Putin," he said of Trump's devotion to the Russian leader, joking: "I'm worried he [gave] Putin one of the 50 states."

Fallon noted how Trump seemed nervous, which “makes sense... because most people are nervous when meeting their boss”.

Late Show host Colbert was also unhappy with Trump's meeting, commenting: "It's really upset people across the partisan divide in ways that I have not seen in years... these are the worst reviews I've ever seen since Titanic... and I'm not talking about the movie," he said.

Former California Gov. and Terminator star Arnold Schwarzenegger said Trump acted like a "fanboy" of Putin in the "embarrassing" press conference.

"You stood there like a little wet noodle, like a little fan boy," he said in a Twitter video directed at Trump. "I was asking myself when you are going to ask him for an autograph or a selfie or something like that."

In the 45-second video, Scwarzenegger also accused Trump of attacking the intelligence community and the Justice Department by refusing to denounce Russian interference in the 2016 election.

During the meeting, Trump said Putin had issued a "strong, impressive denial" of Russian interference in the election and claimed he saw "no reason" why Russia should be involved.

"You're the President of the United States. You shouldn't do that," he said. "What's the matter with you?" He then questioned what happened to the "strong words" during the Cold War from former President Ronald Reagan.

"What happened to the strong words and the strength of Ronald Reagan when he stood there at the Berlin Wall and said 'Mr Gorbachev, tear down this wall'?" he asked. "What happened to all of that?"

Back in Washington, Democrats and Republicans alike were quick to condemn Trump for what was branded "one of the most disgraceful performances by an American president in memory," by Senator John McCain.

He said Trump proved not only unable but "unwilling" to stand up to Putin and noted they "seemed to be speaking from the same script" as Trump made "a conscious choice to defend a tyrant."

While McCain's reaction, which included words like "weak" and "disgraceful", was expected; disapproval also came from more unexpected figures such as Republican House leader Paul Ryan.

"There is no question that Russia interfered in our election and continues attempts to undermine democracy here and around the world," he said. "The United States must be focused on holding Russia accountable and putting an end to its vile attacks on democracy."