Donald Trump has sought to "clarify" his public undermining of American intelligence agencies, saying he had misspoken when he said he saw no reason to believe Russia had interfered in the 2016 US election.
"The sentence should have been, 'I don't see any reason why I wouldn't, or why it wouldn't be Russia' instead of 'why it would'," Mr Trump said, in a rare admission of error.
His comment came - amid rising rebuke by his own party - about 27 hours after his original, widely reported statement, which he made at a summit on Monday in Helsinki standing alongside Russian President Vladimir Putin.
"I accept our intelligence community's conclusion that Russia's meddling in the 2016 election took place," Mr Trump said on Tuesday.
But he added: "It could be other people also. A lot of people out there. There was no collusion at all."
Moments earlier, Senate Republican leader Mitch McConnell issued a public reassurance to US allies in Nato and Europe with whom Mr Trump clashed during his frenzied Europe trip last week.
"The European countries are our friends, and the Russians are not," Mr McConnell said.
Mr Trump maintained Tuesday's summit with Mr Putin went "even better" than his meeting with Nato allies.
He said his Nato meeting was "great" but he "had an even better meeting with Vladimir Putin of Russia. Sadly, it is not being reported that way - the Fake News is going Crazy!"
In fact, the reaction in America was immediate and visceral, among fellow Republicans as well as usual Trump critics.
"Shameful", "disgraceful" and "weak" were a few of the comments.
On Capitol Hill, top Republican leaders said they were open to slapping fresh sanctions on Russia but showed no signs of acting any time soon.
"Let's be very clear, just so everybody knows: Russia did meddle with our elections," said House Speaker Paul Ryan.
"What we intend to do is make sure they don't get away with it again and also to help our allies."
In the Senate, Democratic leader Chuck Schumer called for secretary of state Mike Pompeo and other top officials to appear before Congress and tell exactly what happened during Mr Trump's two-hour private session with Mr Putin.
Mr Schumer also urged the Senate to take up legislation to boost security for US elections and to revive a measure passed earlier by the Judiciary Committee to protect special counsel Robert Mueller's investigation into Russian election interference.
Mr Trump's meeting with Mr Putin in Helsinki was his first time sharing the international stage with a man he has described as an important US competitor - but whom he has also praised as a strong, effective leader.
His remarks, siding with a foe on foreign soil over his own government, were a stark illustration of Mr Trump's willingness to upend decades of US foreign policy and rattle Western allies in service of his political concerns.
A wary and robust stance towards Russia has been a bedrock of his party's world view.
But Mr Trump made clear he feels that any acknowledgement of Russia's election involvement would undermine the legitimacy of his election.
Standing alongside Mr Putin, Mr Trump steered clear of any confrontation with the Russian, going so far as to question American intelligence and last week's federal indictments that accused 12 Russians of hacking into Democratic email accounts to hurt Hillary Clinton in 2016.
Mr Trump said on Monday: "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 just said it's not Russia. I will say this: I don't see any reason why it would be."
His Monday statement drew a quick rebuttal from his director of national intelligence Dan Coats.
"We have been clear in our assessments of Russian meddling in the 2016 election and their ongoing, pervasive efforts to undermine our democracy, and we will continue to provide unvarnished and objective intelligence in support of our national security," Mr Coats said.
President Donald Trump has hit back at criticism of his meeting with Russia's President Vladimir Putin.
The president calls the Monday summit in Helsinki "even better" than his meeting with Nato allies last week in Brussels.
Mr Trump is facing bipartisan criticism for his refusal to publicly challenge Mr Putin over Russia's election hacking and for doubting US intelligence agency conclusions about Russian meddling in the 2016 campaign.
Trump backers, including House Speaker Paul Ryan, Senate Foreign Relations Chairman Bob Corker, and former House Speaker Newt Gingrich have criticised his performance.
Mr Trump took aim at a familiar target, the media, saying his Nato meeting was "great" but that he "had an even better meeting with Vladimir Putin of Russia. Sadly, it is not being reported that way - the Fake News is going Crazy!"
The US president openly questioned his own intelligence agencies' finding that Russia meddled in the 2016 US election, seeming to accept Mr Putin's insistence that Moscow's hands were clean.
The reaction in the United States was immediate and visceral among fellow Republicans and usual Trump critics.
"Shameful," "disgraceful," and "weak" were a few of the comments, while senator Bob Corker said it makes the US "look like a pushover".
In an interview with Fox News' Sean Hannity broadcast on Monday evening, Mr Trump said "it's a shame" that he and Mr Putin were being asked questions about the Russia probe while they were trying to discuss issues like Syria and nuclear proliferation.
"We've had a phony witch hunt deal drive us apart," he said.
Standing alongside Mr Putin in Helsinki, Mr Trump steered clear of any confrontation with the Russian, going so far as to question American intelligence and last week's federal indictments that accused 12 Russians of hacking into Democratic email accounts to hurt Hillary Clinton in 2016.
"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 just said it's not Russia. I will say this: I don't see any reason why it would be," Mr Trump said.
His scepticism drew a quick formal statement, almost a rebuttal, from Mr Trump's director of national intelligence, Dan Coats.
"We have been clear in our assessments of Russian meddling in the 2016 election and their ongoing, pervasive efforts to undermine our democracy, and we will continue to provide unvarnished and objective intelligence in support of our national security," Mr Coats said.
Fellow Republican politicians have generally stuck with Mr Trump during a year and a half of turmoil, but he was assailed as seldom before as he returned home on Monday night from what he had hoped would by a proud summit with Putin.
Senator John McCain of Arizona was most outspoken, declaring that Mr Trump made a "conscious choice to defend a tyrant" and achieved "one of the most disgraceful performances by an American president in memory".
Mr Ryan, who rarely criticises Mr Trump, stressed there was "no question" that Russia had interfered.
Even staunch Mr Trump backer Newt Gingrich, the former House speaker, called the president's comments "the most serious mistake of his presidency" and said they "must be corrected - immediately".
As he flew home to Washington aboard Air Force One, Mr Trump tried to clarify his position via tweet, saying: "As I said today and many times before, 'I have great confidence in my intelligence people.'
"However, I also recognise 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!"
