Giuliani warned that Sessions and Rosenstein had one last chance on Friday to "redeem themselves."
Since joining Trump's legal team in April, Giuliani has distinguished himself from the president's other attorneys with his frequent promotion of unfounded claims.
"I don't believe Mrs. Trump has ever discussed her thoughts on anything with Mr. Giuliani," Melania Trump's spokeswoman said.
"You misogynistic fool," Mika Brzezinski said. "Are you kidding me? 'Just look at Stormy Daniels?' Just look at yourself. Are you kidding me?"
The historic summit has already been endangered once by incendiary remarks from Trump's White House.
"The guy made a mistake," Giuliani said. "He corrected it."
The president is capable of obstructing justice, scholars say, despite the claims of the commander in chief's personal lawyers.
Joe Scarborough said suggesting the president's "sworn political enemy" be shot was "literally out of a tyrant's playbook."
The president's lawyer said they needed to know more about the FBI informant.
"At best here, what we have is complete naïveté and ignorance of how the world works and what's legal and not legal."
Joe Scarborough said Trump has no great plan behind bringing in Giuliani.
Rudy Giuliani has appeared on a variety of news shows over the past week.
The president and his attorneys have provided conflicting accounts about the payment and what Donald Trump knew about it.
Conservative commentators and longtime Trump defenders have questioned the president's honesty in the wake of the Giuliani confession.
Rudy Giuliani has insisted the payment made to Stormy Daniels days before the 2016 election was not a campaign contribution.
Rudy Giuliani has tried to "negotiate an end" to a Justice Department probe before.
Now that he is a private citizen, Comey can address the still murky connections between the New York FBI office, elements of the New York Police Department and Donald Trump.
Geoffrey Berman will succeed Preet Bharara, at least temporarily.
Does the president's delayed rollout also "put our country in peril"?