Fresh from playing Russiagate prober Robert Mueller in a Saturday Night Live skit, Robert De Niro has taken another swing at Donald Trump, branding the US president a “total loser” and “wannabe gangster”.

“I have no other way to say it, I guess. It’s a civic duty. It’s my civic obligation to play Mueller,” De Niro told Late Show host Stephen Colbert.

“I’m hoping that it goes further. I don’t know what’ll happen, but I keep saying that I don’t know whether this is actually possible in reality, where I can handcuff him and take him away in an orange jumpsuit.”

“Why won’t you give the president a chance, Robert De Niro?” Colbert jokingly queried.

“That’s what I said right after he was elected, ‘Give him a chance.’ I give everybody the benefit of the doubt. This guy has proven himself to be a total loser,” offered De Niro, not mincing words.

The Hollywood actor has been involved in a long-running dispute with the current occupant of the Oval Office, famously yelling “f*** Trump” at the Tony Awards last year.

Before that, when Mr Trump was still a presidential candidate, De Niro delivered an online rant about how much he would like to punch him in the nose.

https://www.youtube.com/watch?v=hFpFDyKeqyA

Mr Trump responded to De Niro’s latest diatribe by dismissing him as “a very low IQ individual”.

De Niro, 75, wasn’t quite done, aiming another dig at the President after telling Colbert he had tried giving Mr Trump a chance.

He said: “That’s what I said right after he was elected. Give him a chance. I give everybody the benefit of the doubt. This guy has proven himself to be a total loser.”

De Niro is one of the most revered actors of his generation, winning two Academy Awards for his work on The Godfather Part II and Raging Bull.

He will return to the gangster genre for Netflix’s The Irishman, which will see him once again working with director Martin Scorsese.

Colbert asked De Niro why audiences are so enamoured with gangster flicks, prompting the actor to fire off another barb at Mr Trump.

“People like the outlaw type thing – except we have a wannabe gangster in the White House now,” he said.

De Niro also called Mr Trump a “dumbbell”, adding: “Even gangsters have morals and they have ethics.

“They have a code and you know when you give somebody your word it’s your word because it’s all you have is your word.

“This guy he doesn’t even know what that means.”

-with AAP