President Donald Trump says the economy is improving and job numbers are up, despite the "phony Witch Hunt" against him.
In a series of statements on Twitter on Thursday, Mr Trump repeated his claim that Mr Mueller's investigation is a "WITCH HUNT" based on the "phony" premise of possible collusion between Russian Federation and a cadre of Trump campaign associates.
The new allegations against Trump center on his own admission that he fired Comey because of the Russian Federation investigation, and suggestions he asked several top intelligence officials for their help altering the inquiry's direction.
Comey testified under oath to the Senate intelligence committee earlier in June that Trump told him in a private conversation: "I hope you can see your way clear to letting this go, to letting Flynn go".
Earlier on Thursday, Mr Trump tweeted that a new report suggesting that special counsel Robert Mueller may investigate him for possible obstruction of justice after he fired FBI Director James Comey is a "phony story".
He was also involved into the Iran-Contra and the Watergate investigations.
On Wednesday, the Washington Post reported Mueller is investigating Trump directly, over alleged obstruction of justice.
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The intelligence committee is the lead congressional panel on the Russian Federation hacking scandal, including highly publicized hearings with fired FBI Director James Comey and Attorney General Jeff Sessions. Trump cited the memo in firing Comey.
The Associated Press said Mr Mueller was among the candidates Mr Trump interviewed to replace Mr Comey.
The Trump tweets come after the top lawyer for his transition team warned organization officials to preserve all records and other materials related to the Russian Federation probe.
Trump, who has hired his own lawyer for probes by a special counsel and congressional committees, lashed out on Thursday after a report he was under investigation for possible obstruction of justice.
The newspaper said the information came from officials who spoke on condition of anonymity because they were not authorized to speak publicly. President Trump conceded in an interview after the episode that he was thinking about the Russian Federation controversy when he made that decision.
The Post reported that FBI agents and federal prosecutors are also looking into the financial dealings of Flynn, former campaign chairman Paul Manafort and former campaign policy adviser Carter Page.
The White House has directed questions for details to outside legal counsel, which has not responded.
A representative for Trump's lawyer promptly reacted to the allegation.