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

De Niro 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, 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."

He did not elaborate on his comment and switched immediately to a prepared introduction of Springsteen. "Bruce, you can rock the house like nobody else," De Niro said.

"And 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."

The expletive, known as the F-bomb, was bleeped by the CBS network for millions of television watchers at home.

However, it was heard by those in the audience and journalists covering the awards show, which honours the best of Broadway theatre, and it quickly became the top trending item on Twitter.

De Niro is one of the most respected actors in the US with two Oscar wins for Raging Bull and The Godfather: Part II.

"Mr De Niro's comments were unscripted and unexpected," CBS said in a statement. "The offensive language was deleted from the broadcast."

The White House did not immediately return a request for comment.

De Niro, a noted liberal, has been increasingly critical of Trump, a Republican, at smaller showbusiness events, but none have the high profile and audience of the Tony Awards.

Cursed Child wins

Harry Potter and the Cursed Child won the Tony Award for best play on Sunday while Glenda Jackson and Andrew Garfield took home acting prizes and rocker Bruce Springsteen received a special prize at Broadway's honours for the best in theatre.

Besides the top prize, Harry Potter," a record-setting $69 million production set 19 years after the last of J.K. Rowling's best-selling novels about the boy wizard, won another five Tonys including best director.

Garfield won best actor in a play for his acclaimed performance in the Angels in America revival, a monumental two-part drama about AIDS during the Reagan years.

Angels in America was named best play revival on Sunday. Reuters