High-profile supporters of President Donald Trump are turning on special counsel Robert Mueller, the man charged with investigating Russian interference in the US election and possible collusion with Trump's campaign. The attorney general is expected to be closely questioned about his contacts with Kislyak and his role in last month's firing Federal Bureau of Investigation director James Comey.
Mr Comey told Congress last week he believed he was sacked by Mr Trump to undermine the agency's Russian Federation probe.
The newspaper reported on Wednesday that director of national intelligence Dan Coats, head of the National Security Agency Mike Rogers, and former deputy director at the NSA Richard Ledgett, had agreed to be interviewed by Mr Mueller's investigators as early as this week.
In testimony on Capitol Hill last week, Comey said Mueller had a copy of that memo and several others Comey had written about his interactions with Trump. Still, he added, "I can't imagine that that issue is going to arise".
On Tuesday, Rosenstein also indicated his conversations with Sessions prior to Comey's dismissal could be a part of Mueller's probe.
White House frustrations with the Justice Department spilled into public view last week, when Trump on Twitter criticized the legal strategy in defending his proposed travel ban.
Mark Corallo, a spokesman for Trump's personal lawyer, responded Wednesday evening to the Post report by saying, "The FBI leak of information regarding the president is outrageous, inexcusable and illegal". The comments come amid increasing frustration at the White House and among Trump supporters that the investigation will overshadow the president's agenda for months to come - a prospect that has Democrats salivating.
"I'd be surprised if he did that", the Wisconsin Republican said in an interview on the "Hugh Hewitt Show."
"It's my judgment that I was sacked because of the Russian Federation investigation", Comey said. "But they've chosen the wrong man". He served two additional years beyond his 10-year term, to ensure stability during a transition period in President Obama's national security team. "I hope this is merely the appearance of impropriety, though that is enough to trigger the regulation, and that this isn't just another deep-state scam created to subjugate forever the half of the country that, in desperation, sent Donald Trump to Washington to try and break the establishment's death grip on power".
Mr Trump previously claimed he was the victim of a "witch hunt" in May after Mr Mueller, a former FBI director, was appointed to lead an investigation into his campaign's alleged ties to Russian Federation.
Comey said he believed Mueller would look into Trump for obstruction of justice.
Obstruction of justice is the crime of taking actions to interfere with an official investigation.
On Thursday, Russian President Vladimir Putin said Mr Comey had presented no evidence to prove that Moscow meddled in the United States election, adding that Washington had tried to influence Russian elections "year after year".
But Deputy Attorney General Rod Rosenstein, who appointed Mueller last month, testified Tuesday he has seen no evidence of good cause to fire Mueller.