Rosenstein is overseeing the investigation into Russian meddling, though it is being spearheaded by a special prosecutor, Robert Mueller.
Mueller has assembled a high-powered team of top investigators and leading experts, including seasoned attorneys who've represented major American companies in court and who have worked on cases ranging from Watergate to the Enron fraud scandal.
"I am being investigated for firing the FBI Director by the man who told me to fire the FBI Director!" "The tweet from the president was in response to the five anonymous sources that were purportedly leaking information to the Washington Post about a potential investigation of the president", Sekulow told Chuck Todd.
"Witch Hunt", the president said on Twitter.
Trump advisers and confidants describe the president as increasingly angry over the investigation, yelling at television sets in the White House carrying coverage and insisting he is the target of a conspiracy.
President Donald Trump acknowledged on Friday he is under investigation in a probe of alleged Russian meddling in the 2016 US presidential race and possible collusion by his campaign - and seemed to assail the Justice Department official overseeing the inquiry.
Trump's tweets following the report appeared to confirm the investigation, but his lawyer said it only appeared that way because of the character limit on Twitter.
The Democratic National Committee called on Rosenstein to recuse himself from the Russian Federation matter, but it said authority over the investigation should be given to Mueller and not another Trump appointee.
Rosenstein was among those who advised Sessions to recuse himself, according to officials briefed on the matter.
Although the White House initially said Rosenstein's memo led Trump to fire Comey, the president later said he did so because of the Russian Federation investigation.
The White House has used a memo written by Mr Rosenstein to justify Mr Trump's decision to sack Mr Comey, but that Trump action may now be part of the probe. Attorneys at WilmerHale also represent family members of President Donald Trump, according to Politico. What is clear is that he could order the Justice Department to ax Mueller, which may result in Rosenstein's departure and would certainly intensify the uproar over the investigation. Those associates include former national security adviser Michael Flynn, campaign chairman Paul Manafort, foreign policy aide Carter Page and outside adviser Roger Stone. Trump had viewed Sessions' recusal as unnecessary, even though Justice Department regulations made it nearly impossible to avoid. A day later, Mr Rosenstein appointed Mr Mueller, who was at the helm of the Federal Bureau of Investigation during the September 11 attacks, as special counsel. And it's up to him to decide how much to tell Rosenstein about the substance of the investigation itself.
Trump on Thursday tweeted that the investigation was "the single greatest WITCH HUNT in American political history - led by some very bad and conflicted people!" Trump said on Twitter.
Friday morning, Trump attacked the allegations in a tweet, saying "nobody has been able to show any proof".