US President Donald Trump has said he accepts that Russia sought to influence the 2016 US election, and claimed he misspoke by appearing to accept Vladimir Putin's denials over those of his own intelligence chiefs.
"I have felt very strongly that while Russia's actions had no impact at all on the outcome of the election, let me be totally clear in saying that - and I've said this many times - I accept our intelligence community's conclusion that Russia's meddling in the 2016 election took place," Mr Trump said, before a meeting with Republican politicians at the White House.
In an extraordinary postscript to yesterday's joint news conference in Helsinki, Mr Trump went on to claim that he misspoke when he appeared to take the Russian leader's denial of interference at face value.
Insisting he had won the race fair and square, Mr Trump said yesterday: "I have President Putin, he just said it is not Russia. I will say this: I don't see any reason why it would be."
Today, he offered a laborious explanation for his remarks, which triggered a firestorm, both among opposition Democrats and members of his own Republican Party.
"I actually went out and reviewed a clip of an answer that I gave, and I realise that there is need for some clarification," Mr Trump said.
"I thought it would be obvious but I would like to clarify just in case it wasn't. In a key sentence in my remarks I said the word 'would' instead of 'wouldn't'."
"The sentence should have been, 'I don't see any reason why I wouldn't, or why it wouldn't be Russia.'"
"So just to repeat it, I said the word 'would' instead of 'wouldn't' and the sentence should have been - and I thought it would be maybe a little bit unclear on the transcript or unclear on the actual video - the sentence should have been, 'I don't see any reason why it wouldn't be Russia.'"
US intelligence officials and senior Republicans have denounced the president as "shameful" and "disgraceful" after he refused to challenge Mr Putin over the claims.
Republican Senator John McCain said Mr Trump's seeming acceptance of Mr Putin's denial was a historic "low point" for the US presidency and the Helsinki summit between the two leaders was a "tragic mistake".
"Today's press conference in Helsinki was one of the most disgraceful performances by an American president in memory. The damage inflicted by President Trump's naivete, egotism, false equivalence, and sympathy for autocrats is difficult to calculate," Mr McCain said.
"No prior president has ever abased himself more abjectly before a tyrant."
Taking direct issue with the president who appointed him, Director of National Intelligence Dan Coats said US spy agencies had been "clear" and "fact-based" in their assessment that Russia interfered in the presidential race two years ago - an assessment that Mr Trump refused to endorse in Helsinki.
Mr Coats added that Russia remained behind "ongoing, pervasive efforts to undermine our democracy".
Mr Trump stunned US political allies and foes alike with his answer to a question about Russian hacking and interference in the 2016 election.
"[Mr Putin] just said it is not Russia. I will say this: I don't see any reason why it would be," Mr Trump said.
That came just three days after the US Justice Department indicted 12 Russians for hacking Democratic Party computers.
It was the latest in a series of actions taken by the US government since late 2016 in retribution for what intelligence agencies say was a broad plan to support Mr Trump's election campaign directed by Mr Putin himself.
Yet, Mr Trump appeared to take Mr Putin's word in dismissing that conclusion.
"I have great confidence in my intelligence people. But I will tell you that President Putin was extremely strong and powerful in his denial today," he said.
Mr Trump also appeared to embrace Mr Putin's offer to have Russian investigators work together with US prosecutors on the case of the 12 just indicted.
"I think that's an incredible offer," he told reporters.
As I said today and many times before, "I have GREAT confidence in MY intelligence people." However, I also recognize that in order to build a brighter future, we cannot exclusively focus on the past – as the world’s two largest nuclear powers, we must get along! #HELSINKI2018— Donald J. Trump (@realDonaldTrump) July 16, 2018
My statement on today's summit in Helsinki. pic.twitter.com/WSxFGDKMau— Mitt Romney (@MittRomney) July 16, 2018
Well, now we know. https://t.co/olQlhzQiuO— Hillary Clinton (@HillaryClinton) July 16, 2018
Republicans and Democrats uniformly condemned Mr Trump, with harsh criticism coming even from hosts on Fox News - a network normally friendly to the president.
"The president must appreciate that Russia is not our ally," said Republican House Speaker Paul Ryan.
"There is no moral equivalence between the United States and Russia, which remains hostile to our most basic values and ideals," he said.
Senior Republican Senator Lindsey Graham said Mr Trump's answer on meddling "will be seen by Russia as a sign of weakness".
Bent on forging a personal bond with the Kremlin chief, Mr Trump headed into the summit blaming the "stupidity" of his predecessors for plunging ties to their present low.
"This is shameful," said Senator Jeff Flake, a fellow Republican and staunch critic of the president.
"I never thought I would see the day when our American president would stand on the stage with the Russian president and place blame on the United States for Russian aggression."
The language used by Democrats was much harsher, including accusations of "treason".
"For the president of the United States to side with President Putin against American law enforcement, American defence officials, and American intelligence agencies is thoughtless, dangerous, and weak," said Chuck Schumer, the senior Democrat in the Senate.
Democratic California Representative Jimmy Gomez charged: "To side with Putin over US intelligence is disgusting; to fail to defend the US is on the verge of treason."
Congressman Adam Schiff, the senior Democrat on the House Intelligence Committee, said Mr Trump had given Putin "a green light to interfere in 2018".
Mr Coats' statement was seen as an uncommonly brusque pushback by the US intelligence community against the White House.
Retired spy chiefs were more direct however.
Mr Coat's predecessor, James Clapper, called Mr Trump's acquiescence to Mr Putin "an incredible capitulation," while former CIA chief John Brennan labelled it "nothing short of treasonous".
In a later interview with Sean Hannity on the Fox News channel, Mr Trump repeated his denial that there was collusion with Russian interference in the 2016 election.
He also said Mr Putin had been "very, very strong" in their meeting in Helsinki.
Meanwhile Mr Trump will host the head of the European Commission at the White House later this month to discuss trade and other economic issues, the White House has said in a statement on Tuesday.
Mr Trump and the commission President Jean-Claude Juncker "will discuss a wide range of priorities, including foreign and security policy, counter-terrorism, energy security, and economic growth" at the meeting on 25 July, according to the statement.