US President Donald Trump has said the second woman to accuse his Supreme Court nominee Brett Kavanaugh of sexual abuse when they were young was not credible because she was "drunk" at the time.

"The second accuser has nothing. She thinks maybe it could have been him, maybe not," Mr Trump said.

He added: "She admits that she was drunk. She admits that there are time lapses."

Mr Trump questioned the credibility of the woman, Deborah Ramirez, who is the second to accuse his Supreme Court pick of sexual misconduct.

Ms Ramirez accused Mr Kavanaugh in an article published in the New Yorker magazine on Sunday of exposing himself to her at a drunken party during the 1983-84 academic year at Yale University.

The Senate Judiciary Committee has scheduled a hearing for Thursday for Mr Kavanaugh and Christine Blasey Ford, who last week accused him of sexual assault in 1982.

Mr Kavanaugh has denied the accusations of both women.

"He was so truthful," Mr Trump said about Mr Kavanaugh's interview on Fox News on Monday in which the judge said he had "neve sexually assaulted anyone."

Mr Trump also praised the judge, and accused Democrats of portraying Mr Kavanaugh as someone he is not.

"He is a high-quality person, he is a great intellect," Mr Trump said in remarks to reporters at the United Nations.

Mr Kavanaugh last night said he would not step aside after the allegations.

"The truth is I've never sexually assaulted anyone, in high school or otherwise," Mr Kavanaugh said in an interview on Fox News's "The Story with Martha MacCallum".

The allegations, dating back to the 1980s, have put in jeopardy Mr Kavanaugh's chances of winning confirmation to the top US court in a Senate narrowly controlled by Mr Trump's party, with high-stakes congressional elections just weeks away.

Christine Blasey Ford accused Brett Kavanaugh of sexual misconduct

Confirmation of the federal appeals court judge to the lifetime job would cement conservative control of the Supreme Court and advance Mr Trump's goal of moving the high court and the broader federal judiciary to the right.

The Senate Judiciary Committee has scheduled a hearing for Thursday for Mr Kavanaugh and Ms Ford, who last week accused him of sexual assault in 1982.

Dr Ford, a psychology professor at Palo Alto University in California, said Mr Kavanaugh attacked her and tried to remove her clothing while he was drunk at a party when he was 17 years old and she was 15 when they were high school students in Maryland.

"I am not questioning and have not questioned that perhaps Dr Ford at some point in her life was sexually assaulted by someone at some place, but what I know is I've never sexually assaulted anyone," Mr Kavanaugh said in the interview.

He said he was not present at a party like the one described by Ms Ford and noted that others Dr Ford said were at the gathering had no recollection of it.

"I want a fair process where I can defend my integrity and I know I'm telling the truth. I know my lifelong record and I'm not going to let false accusations drive me out of this process. I have faith in God and I have faith in the fairness of the American people," Mr Kavanaugh said.

He said he "did not have sexual intercourse or anything close to sexual intercourse in high school or for many years thereafter".

Mr Kavanaugh and his Republican allies portrayed the allegations as part of a "smear campaign" by Democrats who have fought his nomination from the outset.

Senate Majority Leader Mitch McConnell made clear that, no matter what happened at the hearing, the full Senate would vote on Mr Kavanaugh's confirmation.

"This fine nominee to the Supreme Court will receive a vote in this Senate in the near future," Mr McConnell said on the Senate floor.

"Senate Democrats and their allies are trying to destroy a man's personal and professional life on the basis of decades-old allegations that are unsubstantiated and uncorroborated," he said.

Mr Trump, himself accused during the 2016 presidential race of sexual misconduct with numerous women, twice offered words of support for Mr Kavanaugh while in New York to attend the UN General Assembly.

"Judge Kavanaugh is an outstanding person. I am with him all the way," Mr Trump said, calling the allegations politically motivated.