Subpoena filed for sexual assault is 'fake news': Trump

US President Donald Trump has said that a subpoena filed against him for alleged sexual assault is " fake news".

"All I can say is it's totally fake news. It's just fake. It's fake," Trump told reporters at a White House news conference responding to a question if his campaign is being subpoenaed for any documents relating to sexual harassment allegations made against him.

Trump slammed such news reports.

"It's made-up stuff, and it's disgraceful what happens. But that happens in the world of politics," he said.

In March this year, former "Apprentice" contestant Summer Zervos, accused Trump of aggressively kissing and grabbing her when she met with him to discuss a possible job at the Trump Organisation after her run on his hit television show, Fox news reported.

Subsequently, the Trump campaign was subpoenaed.

Filed on September 19, the subpoena asked the Trump campaign and its affiliates to hand over documents on Zervos and her associates as well as on "any woman alleging that Donald J Trump touched her inappropriately."