De Niro's expletive, also called the "F-bomb", was bleeped by the CBS television network for millions of television watchers.
In 2016, when Trump was the Republican presidential candidate, De Niro slammed him as "blatantly stupid", "totally nuts", and an "idiot". "It's no longer 'down with Trump, ' 'it's 'f_ Trump'".
After gasps, the audience erupted into applause and gave De Niro a standing ovation.
"Boy, do we need that now".
"With regards to the news today, sir, I have only two words for you: Thank you", said Toronto Mayor John Tory to De Niro.
Kim Jong Un Surprises Crowds in Singapore With Late-Night Tour
Kim smiled as he took a selfie with Singapore's Foreign Minister Vivian Balakrishnan at the scenic waterfront Gardens by the Bay. The secretary of state has traveled to Pyongyang twice to meet with Kim and will participate in the Singapore talks.
Bitcoin falls over 50%, cryptocurrencies lose $46 billion after South Korean hack
Bitcoin was trading at around $6,750 in early afternoon trading in Asia. Bitcoin (BTC) dropped almost $1,000 and -11.5%, in 24 hours.
Cosmic Rival? Astronomers Spot Enigmatic System with Three Earth-Size Planets
Though unique in its own way, this "epic" planet is one of 22 other confirmed exoplanet systems with the same dimensions. This is the first of its kind spectrograph in the country, which can measure the mass of a planet going around a star.
And the more level-headed commenters pointed out the ultimate hollowness of De Niro's habitual statement.
"I do think he speaks to the frustration, anger of a lot of people in this country on the left and the right", Seawright said.
The two-time Academy Award-winner was in Toronto Monday to promote Nobu Residences, his restaurant, hotel and condo project in conjunction with top chef Nobu Matsuhisha.
Trump took to Twitter to blast Trudeau, calling him "very dishonest and weak" shortly after leaving the summit early aboard Air Force One.
De Niro has been an outspoken critic of Trump in the past.
While on The View, Meghan McCain said: 'When you are talking about how Trump's degrading our national discourse with his language, this is not the way to combat Trump, it only helps him'.