Oscar-winning actor Robert de Niro issued an expletive-laden denunciation of US President Donald Trump during the live television broadcast of the Tony Awards ceremony on Sunday.

De Niro, a staunch Trump opponent, appeared on stage at New York's Radio City Music Hall to introduce rocker and Tony Awards performer Bruce Springsteen.

"I'm gonna say one thing. F--- Trump," De Niro said, double fists raised and without any preamble.

With the audience of theatre actors, directors and producers shrieking and rising to their feet in applause, De Niro said: "It's no longer down with Trump. It's f--- Trump."