Donald Trump on Thursday denied urging James Comey, former head of the Federal Bureau of Investigation, to halt a probe into Michael Flynn, his first national security adviser.
Asked at a press conference if he had put any pressure on Mr Comey — who was fired last week — to shut down the Flynn probe, Mr Trump responded: “No, no. Next question.”
Speaking alongside Juan Manuel Santos, the Colombian president, Mr Trump said the move to name a special counsel to take over the FBI investigation into ties between his campaign aides — including Mr Flynn — and Russia was a “witch hunt”.
Rod Rosenstein, the deputy attorney-general, on Wednesday appointed Robert Mueller, a former FBI director, as the special counsel. Mr Rosenstein began overseeing the investigation after Jeff Sessions, the attorney-general and Trump campaign adviser, recused himself.
“I respect the move, but the entire thing has been a witch hunt,” said Mr Trump. “Even my enemies have said there is no collusion.”
Mr Mueller was named eight days after Mr Trump fired Mr Comey and sparked the most serious crisis of his presidency. The White House originally said Mr Comey was fired because of how he had handled an investigation into Hillary Clinton, Mr Trump’s rival in the election race. But Mr Trump later declared that he had dismissed Mr Comey partly because of what he called the “Russia thing”.
Mr Comey’s dismissal prompted claims that Mr Trump was obstructing justice. But the controversy escalated after it emerged that Mr Comey had written a memo after a private meeting with Mr Trump, in which he said the president had urged him to halt an investigation into Mr Flynn.
Mr Trump fired Mr Flynn, who was already under FBI investigation, following a report in the Washington Post that the retired general had lied to vice-president Mike Pence about conversations he had held with the Russian ambassador before the presidential inauguration.
Asked if any of his conduct merited the talk about impeachment that has become more common in Washington in recent days, Mr Trump said: “It is totally ridiculous.”
Earlier on Thursday, Mr Rosenstein told senators at a special briefing about the firing of Mr Comey that he had learnt about the move the day before he wrote a memo that was critical of the FBI head. His explanation undermined the original White House claim that the decision to dismiss Mr Comey was based on the recommendations that he had outlined in the memo.
Following the briefing, Lindsey Graham, a South Carolina senator and former prosecutor, said the appointment of a special counsel would make it difficult for Congress to proceed with its investigations into Russia’s interference with the presidential race.
Several congressional committees have been investigating different strands of the Russia allegations and also looking into possible ties between Trump aides and the Kremlin during the campaign. But Mr Graham said it would be hard for Congress to get witnesses to comply with subpoenas now that Mr Mueller was conducting an independent criminal probe.
When Marco Rubio, the Florida senator who ran against Mr Trump for the GOP presidential nomination, was asked after the briefing about Mr Trump’s “witch hunt” comment, he said that “the president is entitled to his own opinion but we are a nation of laws”.
Congressional committees have the power to grant immunity to witnesses in order to obtain their testimony or relevant documents. But doing so can make it all but impossible to prosecute them later for potential criminal offences discussed in public hearings on Capitol Hill.
“If I was Mr Mueller I would jealously guard the witness roll,” said Mr Graham. “Congress is going to have to be very leery about crossing into Mr Mueller’s lane.”
Lawmakers learnt that lesson the hard way during the 1987 Iran Contra hearings into the Reagan administration’s use of the proceeds of arms sales to Iran to illegally fund the Contra rebels in Nicaragua. Congress granted John Poindexter, the national security adviser, and aide Oliver North limited immunity, meaning prosecutors could not use their congressional testimony in a criminal proceeding.
Lawrence Walsh, the independent counsel, pleaded with lawmakers to delay their public hearings so his criminal probe could proceed, according to John Barrett, a lawyer on his staff. Both men were later convicted, but the convictions were overturned on appeal. Judges ruled that witnesses had been tainted by exposure to public testimony.
“In Iran-Contra, Walsh spent a lot of time asking the committees not to grant immunity and in the end the committees decided to go ahead,” said Mr Barrett, a law professor at St John’s University in New York. “That’s ultimately what sank the Poindexter and North convictions.”
Follow Demetri Sevastopulo on Twitter:@dimi