Donald Trump has backtracked on his claim that he "didn't see any reason" why Russia would be involved in US election meddling.
This evening he said that what he meant to say was he didn't see any reason why Russian wouldn't be responsible for meddling in the 2016 vote.
Mr Trump said: "I realise there's a need for some clarification", adding that what he meant "should have been obvious – I thought it would be obvious but would like to clarify in case it wasn't".
"In a key sentence in my remarks I said the word 'would' instead of 'wouldn't'."
Mr Trump was speaking after returning from the Helsinki summit to widespread anger over his performance during a news conference with Vladimir Putin.
He added that he had "full faith and support" for the US intelligence agencies and "accepts" their conclusion that there was Russian interference but he added: "It could be other people also. A lot of people out there. There was no collusion at all".
"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," he said.
Speaking about Mr Trump's mistake, Sky's US correspondent Hannah Thomas-Peter said: "If we are to believe that (it was a simple mistake), that's not good, because the leader of the free world should be able to nail those important ideas, express himself clearly under pressure when standing next to the leader of an adversarial nation.
"And it's really hard to believe that if it was a simple mistake, one that caused this global uproar, why did the White House leave it for 24 hours before clarifying it when it could have been done in the immediate aftermath of the press conference?"
Again, Mr Trump also denied that his campaign colluded with the Russians at the time.
He had not condemned Russia's interference on Monday, instead saying: "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."
Almost as soon as the words were spoken, journalists, political commentators and politicians expressed bemusement and anger, with some such as former CIA director John Brennan describing them as "treasonous".
Mr Trump is meeting with members of Congress, with many of them having joined the chorus of condemnation.
Speaker of the House, Paul Ryan said earlier: "Let's be very clear – Russia meddled in our election".
Mr Ryan had added that Congress would make sure they were not able to "get away with (election meddling) again".
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Mr Trump's pliable manner at Monday's summit with Russia had been in stark contrast to the combativeness he had displayed towards NATO allies last week, and Mr Ryan felt the need to issue reassurance that the US "stands by NATO allies and all countries facing Russian aggression".
Reacting to Mr Trump's turnaround, Senate minority leader Chuck Schumer said: "24 hours is too late and in the wrong place".