OTTAWA -- Canadian Prime Minister Justin Trudeau said Tuesday that his country will not back down from a fight against the trade war initiated by US President Donald Trump.

Trudeau told a press conference that there is no justification for the trade war Canada and the US are entangled in and Canada will challenge Trump's moves.

"So today, the US launched a trade war against Canada, their closest partner and ally, their closest friend," said Trudeau who repeated Canada's retaliation.

The Canadian government hit back with an initial 30 billion Canadian dollars ($21 billion) in tariffs on US goods, with the promise to add another 125 billion Canadian dollars more in 21 days' time.

Trudeau vowed that American families, and Trump, will soon feel how damaging the tariffs are. Speaking to the camera, Trudeau addressed Trump directly saying that "This is a very dumb thing to do".

Trudeau accused Trump of wanting to "see a complete collapse of the Canadian economy", believing that's the reason Trump is moving ahead so aggressively.

"Because that will make it easier to annex us, is the second part of his thought," said Trudeau, "That is never going to happen."

He called the president's claims the tariffs are needed because of fentanyl seeping across the border from Canada to the US "unjustified and false excuse".

Canadian officials made a month-long diplomatic push to avoid tariffs and has responded to Trump's concerns about the border. Canada named a new "fentanyl czar" and listed Mexican cartels as terrorist groups.

On Feb 1, Trump signed an executive order to impose a 25 percent tariff on goods imported from Mexico and Canada, with a 10 percent tariff increase specifically for Canadian energy products.

On Feb 3, Trump announced that the additional tariffs on goods from Mexico and Canada would be deferred for one month, allowing more time for negotiations.

Trump said Monday that 25 percent tariffs on Mexico and Canada will take effect on Tuesday, March 4.