Washington, Mar 8: US President Donald Trump denies allegations he had an affair with a porn star more than a decade ago and paid for her silence, the White House said.

"The president has denied the allegations against him," press secretary Sarah Sanders told reporters.

"The president has addressed these directly and made very well clear that none of these allegations are true," Sanders said. "Anything beyond that I would refer you to the president's outside counsel."

The lawyer for porn star Stormy Daniels has said that she had a sexual relationship with Trump in 2006 and 2007 and wants to nullify a "hush agreement" so the public can decide "who's telling the truth."