President Donald Trump has mocked the testimony of Christine Blasey Ford against his Supreme Court nominee Brett Kavanaugh at a rally in Mississippi.
"What neighbourhood was it in? I don't know," Trump said. "But I had one beer. That's the only thing I remember. And a man's life is in tatters."
Days earlier he had said Prof Ford was a "credible" and "compelling" witness.
Prof Ford told a Senate committee that Kavanaugh assaulted her as a teenager, an allegation he denies.
Trump ordered the FBI to examine the claims following the Senate testimony.
However, Prof Ford's lawyers say the FBI has not yet spoken to her and say it is "inconceivable" that the agency could conduct a thorough investigation without interviewing her.
The FBI investigation is due to be completed by Friday.
Senate Majority Leader Mitch McConnell has said the Senate must vote on confirming Kavanaugh this week.
What did Trump say?
He told supporters in the town of Southhaven that his political opponents had been "trying to destroy Judge Kavanaugh since the very first second he was announced".
He then mocked Prof Ford's testimony, saying she appeared not to remember basic details about the alleged assault.
The audience laughed as the president said: "Thirty-six years ago this happened: I had one beer! Well, you think it was…? Nope! It was one beer.
"Oh, good. How'd you get home? I don't remember. How'd you get there? I don't remember. Where was the place? I don't remember.
"How many years ago was it? I don't know. I don't know. I don't know! I don't know! What neighbourhood was it in? I don't know.
"Where's the house? I don't know! Upstairs, downstairs, where was it? I don't know! But I had one beer. That's the only thing I remember. And a man's life is in tatters."
Shortly after Prof Ford's dramatic testimony to the Senate committee last week, Mr Trump said she was "very compelling" and described her as a "very fine woman".
Earlier on Tuesday, Trump reiterated his support for Kavanaugh saying he believed the Senate would approve the judge.
He told reporters it was a "very scary time for young men in America when you can be guilty of something that you may not be guilty of".
What does Prof Ford remember?
When she spoke before the Senate committee last Thursday, Prof Ford recalled that the house where the alleged assault took place was in the Chevy Chase-Bethesda area in the wealthy suburbs of Washington DC.
The president seemed to suggest she did not know on what floor of the property the alleged attack had occurred, but Prof Ford told senators she remembered being pushed into a bedroom on the upstairs level.
She testified that it occurred in the summer of 1982. In her initial letter to Senator Dianne Feinstein, she wrote that the assault happened "during high school in the early 1980's".
Arizona prosecutor Rachel Mitchell, who questioned Prof Ford during testimony, said she had told a polygrapher the alleged assault happened in the early 80s, then crossed out the word "early".
Prof Ford did acknowledge in her testimony that she could not provide all the details asked of her - including how she arrived at the party or how she left it and where exactly it took place.
"I don't have all the answers, and I don't remember as much as I would like to," she said. "But the details about that night that bring me here today are ones I will never forget."
Experts have said it is not unusual for victims of trauma to remember certain details vividly but have little recollection of other things that the brain may have accorded less significance to.