US presidential hopeful Donald Trump has laid out an ambitious agenda for his first 100 days in the top job, but pointedly noted that he will also find time to sue the numerous women who have accused him of sexual assaults.

"All of these liars will be sued once the election is over," Mr Trump said on Saturday during an event that was meant to be policy-driven.

"I look so forward to doing that," he said.

In response to Mr Trump's remarks, Hillary Clinton said she was done responding to what her Republican opponent was saying as Election Day nears and would instead focus on helping elect other Democrats.

Jessica Drake (R) listens to questions after giving a statement in which she alleges Republican Presidential candidate Donald Trump sexually harassed her at a 2006 golf event in Lake Tahoe at a press conference held by attorney Gloria Allred in Los Angeles, California. (AAP)

To that end, she attacked Pennsylvania's Republican senator, Pat Toomey, accusing him of refusing to "stand up" to Mr Trump as she praised his Democratic challenger, Katie McGinty.

Noting Mr Trump's comments about Mexican immigrants and his attacks on a Muslim-American military family, she said of Mr Toomey: "If he doesn't have the courage to stand up to Donald Trump after all of this, then can you be sure that he will stand up for you when it counts?"

Mr Toomey's spokesman Ted Kwong said Ms Clinton's comments highlight Ms McGinty's lack of independence.

"Today is just further proof that hyper-partisan, ethically challenged Katie McGinty will be a rubber stamp for everything Hillary Clinton wants to do in Washington," he said.

"Pat Toomey has been, and will continue to be, an independent leader in the Senate on issues ranging from gun safety to ending Wall Street bailouts."

Ms Clinton also rejected Mr Trump's allegation, offered without evidence, that the dozen or so women who have come forward had been prompted by her campaign or the Democratic National Committee.

The accusers emerged after the former reality TV star boasted of kissing women and groping their genitals without their consent.

On Saturday, an adult film actress said the billionaire kissed her and two other women on the lips "without asking for permission" when they met him after a golf tournament in 2006.

Mr Trump has denied that all the other allegations, insisting that some of the women were not attractive enough for him to want to pursue.

His broadside against the women came at the start of an otherwise substantive speech that sought to weave the many policy ideas he has put forward into a single, cohesive agenda.

The Republican nominee vowed to lift restrictions on domestic energy production, label China as a currency manipulator and renegotiate the North American Free Trade Agreement, all familiar themes to supporters who have flocked to his rallies this year.

"This is my pledge to you, and if we follow these steps, we will once again have a government of, by and for the people," Mr Trump said, invoking a phrase from former president Abraham Lincoln's Gettysburg Address.

Though mostly a recap of policies he had already proposed, Mr Trump's speech included a few new elements, such as a freeze on hiring new federal workers and a two-year mandatory minimum sentence for immigrants who re-enter the US illegally after being deported a first time.

In a pledge sure to raise eyebrows on Wall Street, he said he would block a potential merger between AT&T and media conglomerate Time Warner.

Throughout the GOP primary, Mr Trump was criticised for shying away from detailed policy proposals.

But his speech, which aides said would form the core of his closing argument to voters, underscored how the billionaire has gradually compiled a broad - if sometimes vague - policy portfolio that straddles conservative, isolationist and populist orthodoxies.

Still, any headway that Mr Trump may have made was likely to be diluted by his legal threats against his accusers, just the latest example of him stepping on his intended message at inopportune moments.

With AAP.