Before he started the part he was called for, the 74 years old actor shouted on the stage, "I'm just going to say one thing".
"It's no longer down with Trump, it's f-- Trump!"
It was hardly the first time that De Niro, who was born in NY and lives in the city, attacked fellow New Yorker Trump.
The Oscar victor actor added, "It's no longer 'down with Trump.' It's 'f**k Trump!'"
Kate Middleton Comforts Prince George at Polo Game
However, several people on Twitter have shared their outrage as one of the toys Prince George was playing with was a toy gun. Kate Middleton may have access to a wardrobe full of designer duds, but she loves a good bargain as much as the rest of us.
"I just want to make a note of apology for the idiotic behaviour of my president", De Niro said in Toronto while attending a ground-breaking ceremony for a new luxury restaurant and hotel complex.
De Niro was much more candid at the Tony Awards on Sunday night, earning a standing ovation for expletives aimed at the USA president. De Niro said he'd be happy to accept.
American viewers watching the Tonys at home only heard silence - the broadcast on CBS bleeped De Niro's expletive-heavy intro - but they saw the audience's largely enthusiastic reaction, the Associated Press reported. "Boy, do we need that now".
Robert De Niro seemed to be sending a message on behalf of Broadway. Kushner went even further, calling Trump's presidency "the Hitler mistake" that put a "borderline psychotic narcissist in the White House". "Who's gonna argue with him?"
ABC's talk show The View's co-host Meghan McCain also critiqued De Niro: "When you're talking about how Trump is degrading our national discourse with his language, this is not the way to combat Trump, it only helps him".