New York (AFP) - Hollywood megastar Robert De Niro got a standing ovation at the Tony Awards for using an expletive to condemn US President Donald Trump.

The Oscar-winning De Niro, 74, was at the annual event for the top US theater awards late Sunday to introduce a performance from rock legend Bruce Springsteen.

"I'm going to say one thing -- fuck Trump!" De Niro said, pumping his fists in the air.

The crowd at New York's Radio City Music Hall began cheering, then gave him a standing ovation.

"It's no longer 'down with Trump', it's 'fuck Trump'!" he said.

The CBS television network, which was broadcasting the event live but with a delay of a few seconds, bleeped out De Niro's expletive.

The actor then got on with his introduction, praising Springsteen for the singer's political activism.

"Bruce, you can rock the house like nobody else," said De Niro. "Even more important in these perilous times, you rock the vote. Always fighting for, in your own words, truth, transparency, and integrity in government. Boy, do we need that now."

It was hardly the first time that De Niro, who was born in New York and lives in the city, attacked fellow New Yorker Trump.

In 2016, when Trump was the Republican presidential candidate, De Niro slammed him as "blatantly stupid," "totally nuts" and an "idiot."

In response to a Trump statement about handling protesters at one of his rallies, De Niro said: "He wants to punch people in the face? I'd like to punch him in the face!"

And at a 2017 speech at Brown University he described the Trump administration as a "tragic, dumbass comedy."

De Niro won Oscars for his roles in "The Godfather: Part II" (1974) and "Raging Bull" (1980).