US President Donald Trump has dramatically backed down in the face of near universal condemnation of his summit with Vladimir Putin, saying he “misspoke” when he supported the Russian President’s denials of election interference.

At a joint news conference with Mr Putin after their summit Tuesday morning (AEST), Mr Trump stunned both Democratic and Republican politicians by apparently siding with Mr Putin against American intelligence agencies.

High-ranking Republican politicians branded Mr Trump’s comments a “disgrace” and “shameful”, while a former CIA director called them “treasonous”.

Mr Trump made a stunning reversal on Wednesday morning in a bid to counter the mounting criticism.

“In a key sentence in my remarks I said the word ‘would’ instead of ‘wouldn’t’,” the President told reporters after a meeting with Congress at the White House.

“The sentence should have been: ‘I don’t see any reason why it wouldn’t be Russia. Sort of a double negative,” Mr Trump explained, saying he had reviewed a transcript and video of his Helsinki remarks. 

“I think that probably clarifies things pretty good on itself,” he added.

At the joint news conference in the Finnish capital, Mr Trump had said: “I don’t see any reason why it would be” Russia who interfered in the election.

His remarks after meeting Congress were in stark contrast to a tweet he posted earlier Wednesday morning in which he said his meeting with Mr Putin was better than the one he held with his NATO allies earlier in his European trip.

While I had a great meeting with NATO, raising vast amounts of money, I had an even better meeting with Vladimir Putin of Russia. Sadly, it is not being reported that way – the Fake News is going Crazy!

— Donald J. Trump (@realDonaldTrump) July 17, 2018

Speaking at the White House on Wednesday, the President also pledged his support of US intelligence agencies – who have maintained that Moscow actively sought to interfere with the outcome of the 2016 election – but maintained he won the 2016 election on the merits of his campaign.

“I have full faith and support for America’s great intelligence agencies. Always have,” Mr Trump said.

He added that he “felt very strongly that while Russia’s actions had no impact at all on the outcome of the election … I accept our intelligence community’s conclusion that Russia’s meddling in the 2016 election took place.”

“Could be other people also,” Mr Trump said. “There’s a lot of people out there.”

He also called his summit with Mr Putin a success.

Shortly after Mr Trump appeared on the Helsinki podium alongside Mr Putin, veteran Republican Senator John McCain described the President’s pro-Russian rhetoric as “one of the most disgraceful performances by an American president in memory”, while Senator Ben Sasse called it “bizarre”.

Trump ally Newt Gingrich called it, “the most serious mistake” of Mr Trump’s presidency — and one that, “must be corrected immediately”.

Former CIA director John Brennan went so far as to call for Mr Trump to be impeached over his stance at the news conference.

Donald Trump’s press conference performance in Helsinki rises to & exceeds the threshold of “high crimes & misdemeanors.” It was nothing short of treasonous. Not only were Trump’s comments imbecilic, he is wholly in the pocket of Putin. Republican Patriots: Where are you???

— John O. Brennan (@JohnBrennan) July 16, 2018

“Donald Trump’s press conference performance in Helsinki rises to & exceeds the threshold of ‘high crimes & misdemeanors,’ Mr Brennan posted on Twitter, referring to the standard for impeachment outlined in the US constitution.

“It was nothing short of treasonous. Not only were Trump’s comments imbecilic, he is wholly in the pocket of Putin. Republican Patriots: Where are you???”

-with agencies