US President Donald Trump has said he accepts US intelligence agencies' conclusion that Russia interfered in the 2016 election - despite declining to do so just a day ago.

He said he had misspoken on Monday and had meant to say he saw no reason why it was not Russia that meddled.

The original comments, after he met Russian President Vladimir Putin in Helsinki, drew a barrage of criticism.

Even some of Mr Trump's allies had urged him to clarify his stance.

Your toolkit to help understand the story
Trump's 'most serious mistake'
Schwarzenegger calls Trump a 'wet noodle'
'Double negative' is not not trending
In his latest remarks, he added he had "full faith and support" in US intelligence agencies.

What he said then...
The controversy centres on a response he gave to a question at a news conference on Monday following the summit with Mr Putin.

This is an extract from the transcript posted by the White House.

REPORTER: President Putin denied having anything to do with the election interference in 2016. Every US intelligence agency has concluded that Russia did. My first question for you, sir, is, who do you believe?

TRUMP: My people came to me... they said they think it's Russia. I have President Putin; he just said it's not Russia. I will say this: I don't see any reason why it would be.

.... what he says now
Mr Trump said he had reviewed the transcript and realised he needed to clarify.

"In a key sentence in my remarks, I said the word 'would' instead of 'wouldn't," he said.

"The sentence should have been: 'I don't see any reason why I wouldn't' or 'why it wouldn't be Russia'. Sort of a double negative."

The US president added: "I accept our intelligence community's conclusion that Russia's meddling in the 2016 election took place. Could be other people also. A lot of people out there."

Mr Trump said that the interference had had no impact on the election, in which he defeated Hillary Clinton.

However, he did not respond when reporters asked him if he would condemn Mr Putin.

Why the outrage?
Republicans and Democrats alike were dumbfounded that Mr Trump sided with Russia over his own intelligence officials after Monday's summit.

The US and Russia have been long-term adversaries, and remain far apart on major issues. Some lawmakers were also upset that he refused to offer specific criticisms of Russia and Mr Putin, instead saying both countries were responsible for poor relations.

Even one of his most loyal Republican supporters, Newt Gingrich, said the comments were the "most serious mistake of his presidency".

After the reversal, Senate Democratic leader Chuck Schumer accused the US president of cowardice.

The damage has been done
By the BBC's Anthony Zurcher in Washington

Does Donald Trump believe in ominous metaphors? As he affirmed his support for US intelligence agencies, the lights went to black in the White House conference room.

Once order was restored, he said he had been in the dark why a storm has swirled around his presidency in the day since his Helsinki summit with Vladimir Putin. It was, he says, because he misspoke.

That is going to be hard for many of the president's critics to swallow, however. Even if he did mean to say, "I don't see a reason why it wouldn't be Russia", it is a pretty weak way to confront the head of a nation accused of targeting the heart of American democracy.

What's more, the context of the president's comments make a simple slip of the tongue seem less likely.

At the very least, the president gave his supporters some material to rally around.

The damage, however, has been done. Mr Trump can give as many White House statements as he likes, but on the biggest stage - standing beside the Russian president - he fumbled. All the explanations can't change that.

https://www.bbc.com/news/world-us-canada-44864739