- Democratic Senator Kirsten Gillibrand called on Trump to resign, meanwhile, echoing a demand made the previous day by two other Senate Democrats, while a group of 54 Congresswomen backed Trump's accusers in calling for a probe.
The White House on Monday rejected calls for a congressional investigation of claims Donald Trump sexually harassed women, saying the American people had spoken on the matter by electing him president.
Democratic Senator Kirsten Gillibrand called on Trump to resign, meanwhile, echoing a demand made the previous day by two other Senate Democrats, while a group of 54 Congresswomen backed Trump's accusers in calling for a probe.
Three women who claim they were sexually harassed by Trump before he ran for president urged Congress on Monday to investigate his behavior and allegations of misconduct.
The three, who first came forward during last year's presidential race with their claims of harassment, said they were speaking up again because of the current climate.
In recent months, countless women have broken their silence about abuse suffered at the hands of powerful men in the worlds of entertainment, the media, business and politics, in the wake of the bombshell allegations that felled movie mogul Harvey Weinstein.
"The environment's different," said Samantha Holvey, who claims Trump came backstage when she and other contestants in the 2006 Miss USA pageant were dressing.
"Let's try again," Holvey said, in explaining her decision to repeat her allegations.
Rachel Crooks, who says Trump forcibly kissed her on the mouth after she introduced herself to him at Trump Tower in 2005, urged lawmakers to "put aside their party affiliations and investigate Mr. Trump's history of sexual misconduct."
Crooks voiced hope "that we will hold Mr Trump to the same standard of Harvey Weinstein and the other men who were held accountable for their reprehensible behavior."
Jessica Leeds, who says she was groped and forcibly kissed by Trump on a commercial flight decades ago, said the president has not been held accountable for "what he is and who he is."
The White House swiftly dismissed the claims as "false."
"The timing and absurdity of these false claims speaks volumes and the publicity tour that has begun only further confirms the political motives behind them," a White House statement said.
- 'A decisive election' -
Addressing reporters, White House spokeswoman Sarah Huckabee Sanders said the president "has addressed these accusations directly and denied all of these allegations.
"This took place long before he was elected to be president and the people of this country had a decisive election, supported President Trump," Sanders said. "We feel like these allegations have been answered through that process."
Gillibrand, a Democratic senator from New York, told CNN that Trump should "immediately resign."
"President Trump has committed assault according to these women," she said. "And those are very credible allegations.
"I think he should immediately resign and if he doesn't we should have the investigation," Gillibrand said.
Democratic senators Cory Booker of New Jersey and Jeff Merkley of Oregon also called over the weekend for Trump to step down.
Democratic Senator Ron Wyden backed the call for a congressional investigation -- which appeared unlikely to occur given the Republican control of both houses of Congress.
"These women are right," the senator from Oregon said in a tweet. "If @realDonaldTrump won't resign, Congress must investigate allegations by many, many women that he sexually assaulted and harassed them. No one is above the law."
Later Monday, Democratic Congresswoman Lois Frankel said she was leading a contingent of women representatives from the lower chamber in demanding a probe.
"Americans deserve to learn the truth about the Commander in Chief, which is why I'm leading @HouseDemWomen in calling for an investigation in Congress of the sexual misconduct allegations against @realDonaldTrump," she tweeted, linking to a CNN report that a group of 54 women were involved in the effort.
Three US lawmakers announced their resignations from Congress last week over sexual harassment allegations, including Democratic Senator Al Franken of Minnesota.
In announcing his resignation, Franken took aim at Trump.
"I, of all people, am aware that there is some irony in the fact I am leaving while a man who bragged on tape about his history of sexual assault sits in the Oval Office," he said.
A total of 16 women have come forward with claims of misconduct by Trump, who boasted in a tape that surfaced during the campaign that he could kiss and grope women with impunity, because of his celebrity.
In an apparent divergence from the White House line, Nikki Haley, the US ambassador to the United Nations, said Sunday that any women claiming to be victims of sexual harassment -- including those implicating Trump -- "should be heard."