US President Donald Trump has sought to cast doubt on the woman who has accused his Supreme Court nominee Brett Kavanaugh of sexual assault, saying if the attack was “as bad as she says,” it would have been immediately reported to police.

After days of restrained comments on the allegations by California professor Christine Blasey Ford, Mr Trump took to Twitter to question her account of what happened between her and Mr Kavanaugh at a party in 1982 when they were in high school.

The Senate Judiciary Committee had delayed a vote on Mr Kavanaugh’s confirmation after Dr Ford’s allegations emerged last week, and her lawyers and committee staff are negotiating how and when she will testify.

Approval of Mr Kavanaugh would cement conservative control of the Supreme Court and advance a White House effort to tilt the American judiciary farther right.

Mr 
Trump and the White House had been careful not to malign Dr Ford after her allegations surfaced, but Mr Trump dropped the restraint in his tweets on Friday.

I have no doubt that, if the attack on Dr. Ford was as bad as she says, charges would have been immediately filed with local Law Enforcement Authorities by either her or her loving parents. I ask that she bring those filings forward so that we can learn date, time, and place!

— Donald J. Trump (@realDonaldTrump) September 21, 2018

“I have no doubt that, if the attack on Dr. Ford was as bad as she says, charges would have been immediately filed with local Law Enforcement Authorities by either her or her loving parents,” Mr Trump said.

“I ask that she bring those filings forward so that we can learn date, time, and place!

“Judge Brett Kavanaugh is a fine man, with an impeccable reputation, who is under assault by radical left wing politicians who don’t want to know the answers, they just want to destroy and delay,” Trump wrote.

Republican Senator Susan Collins, potentially a key vote on Mr Kavanaugh’s nomination, said at an event in Portland, Maine, that she was “appalled” by Mr Trump’s tweet.

“We know allegations of sexual assault are one of the most unreported crimes that exist,” Ms Collins said, according to the Portland Press Herald.

“So I thought that the president’s tweet was completely inappropriate and wrong,” she said.

I hope that Dr. Ford will reconsider and testify before the Senate Judiciary Committee on Monday. It is my understanding that the Committee has offered to hold either a public or a private session, whichever would make her more comfortable.

— Sen. Susan Collins (@SenatorCollins) September 19, 2018

If the hearing proceeds, Republicans will be forced to walk a careful line in questioning Dr Ford’s account without alienating women voters ahead of the elections.

Before the 2016 presidential election, more than a dozen women accused Mr Trump of making unwanted advances.

-AP