Trump says he has 'never worked for Russia', allegations saying so are a 'big fat hoax'

US President Donald Trump said Monday that he has "never worked for Russia", and slammed recent news reports that have raised questions about his ties to Vladimir Putin as a "big fat hoax."

Trump made his comments to reporters at the White House. 

The US president's comments came after a Washington Post report alleging that Trump had refused to divulge the contents of his meetings with Russian President Vladimir Putin. 

The Post said he had kept details of the meetings even from his top aides. 

The Post however added that there was no proof of wrongdoing by Trump, only that he had kept details of his meetings with Putin from his aides. 

A report in The New York Times meanwhile revealed the FBI had opened an investigation into whether Trump was working for Russia after he sacked the bureau's director James Comey in 2017. 

Trump was given an opportunity to respond to the report of the FBI investigation on Saturday when he gave an interview to his favourite Fox News channel.

But instead of a clear cut denial, he fueled a mounting outcry in Washington by merely saying that the question was "the most insulting thing I've ever been asked."

His response Monday took the entire alleged Russia collusion affair head on.

"It's a lot of fake news," Trump said. He called the then-leaders of the FBI who decided to investigate him "known scoundrels, I guess you could say dirty cops."

But the latest twists mean that the president -- currently embroiled in a damaging political battle with Congress over funding a Mexico border wall -- can't escape the Russia shadow, regardless of what he says.

The details of the latest reports are especially shocking because they are so concrete, in contrast to the often complex and carefully withheld workings of the almost leak-proof Mueller probe.

The Post story says that Trump personally acted to prevent notes taken by his interpreter during one-on-one meetings with Putin from being shared with aides. He allegedly took the notes away and ordered the interpreter not to divulge the contents.

The Times report on the FBI investigation said the bureau decided to act after Trump fired the then director, James Comey in 2017.

Transcripts of closed-door FBI testimony to Congress obtained by CNN show that the then head lawyer for the FBI, James Baker, said the bureau wanted to know whether Trump was "acting at the behest of (the Kremlin) and somehow following directions, somehow executing their will."

"That was one extreme. The other extreme is that the President is completely innocent, and we discussed that too," Baker said in the transcript, according to CNN.

The White House says that Trump has been pursued by a politicized FBI. The president repeatedly has called the probes into his dealings with Russia a "witch hunt."

But Democrats and even some in Trump's Republican Party have repeatedly suggested that the administration is oddly favourable to Russian policies.

They point to Trump's diplomatic assaults on European Union unity and the NATO alliance, as well as his recent comment defending the Soviet occupation of Afghanistan in the 1980s.

Top advisor Kellyanne Conway reiterated Monday the administration's assertion that Trump had in fact been tough on Russia, one of Washington's key rivals and sometimes outright adversaries.

"He has taken a lot of action," she told reporters, listing sanctions imposed on the Kremlin and US policy in Syria, among other factors. 

(With inputs from AFP)