That person met "several times" with campaign national security advisers Carter Page and George Papadopoulos, according to the report, which offered no additional information on the informant's identity or connection with us authorities. At least one government informant met several times with two of Trump's former campaign aides, officials have said.
Mr Trump appeared to be reacting to recent news reports there may have been a top-secret source inside the Trump campaign providing intelligence to the FBI as it began its investigation into Russia's interference in the election process.
He said the legal team was "pretty comfortable, in the circumstances of this case, that they wouldn't be able to subpoena him personally".
Yanny or Laurel? President Trump hears 'Covfefe'
The age of your ears will also affect what you hear, the sounds of "Yanny play at a higher frequency than those of "Laurel". What do you hear?! Story also added that if you change the pitch of the original recording you can hear both words.
The US president made the claim, without any supporting evidence, in a tweet following and earlier post describing the special counsel investigation into potential ties between the Trump campaign and Russian Federation, "the greatest witch hunt in American history".
Mr Giuliani said on Wednesday that the special counsel's team had informed the president's attorneys recently that prosecutors do not believe they can charge a sitting president with a crime under Justice Department guidelines, signalling they would leave it to Congress to address any possible findings of wrongdoing by Mr Trump.
Trump did not provide any evidence beyond the National Review story, which questions the FBI's official account of the investigation's origins and the timing of Simpson's retraction.
WHO raises Ebola health risk to 'very high' in DR Congo
She warned that the disease can be transmitted via human contact with the body fluids of an infected person and is fatal. The risk to countries in the region is now determined as "high", but the global risk remains "low".
"The only Collusion was that done by Democrats who were unable to win an Election despite the spending of far more money!"
It comes the same day Mr Mueller's office was forced to give a federal court a classified memo describing the extent of his investigation.
Rudy Giuliani, one of Trump's lawyers, told The Hill on Thursday that if there was a government informant spying on Trump's campaign it would be no "different that Watergate".
Israel, Palestinians spar over new Jerusalem embassies
Netanyahu said it was fitting, noting that Guatemala also followed the U.S.to be the second country to recognize Israel 70 years ago.
"I think we're going to have to look into whether we can challenge the legitimacy of this entire investigation", Giuliani said. Trump's former national security adviser, Michael Flynn, and his deputy campaign chairman, Rick Gates, have pleaded guilty and are now cooperating with the probe.