US President Donald Trump is seeking more than $U20 million ($26 million) in damages from a porn actress who is trying to void a confidentiality agreement that requires her to keep quiet about her alleged affair with the US president.

Stormy Daniels has breached her confidentiality agreement at least 20 times, the Trump legal team alleged in filings in federal court in Los Angeles.

Essential Consultants, a Delaware company set up by Trump's personal lawyer and fixer Michael Cohen, paid $US130,000 to Daniels 11 days before the November 2016 presidential election in a deal that required her to never speak publicly about the alleged tryst with Trump.

US President Donald Trump is seeking more than $U20 million ($26 million) in damages from a porn actress who alleged affair with the US president. AP

Daniels, 38, sued Trump last week in state Superior Court in Los Angeles in an attempt to get the confidentiality agreement nullified. One of the reasons she cited is that Trump, who went by the alias David Dennison in the nondisclosure pact, did not sign it.

The new papers submitted by Trump's legal team seek to shut down the state court lawsuit and transfer it to federal court. The filings were first reported by The New York Times.