Canadian Prime Minister Justin Trudeau appeared at a loss for words Tuesday, pausing for 20 seconds when pressed for this thoughts on US President Donald Trump's threat of military mobilization against violent US protests.

"We all watch in horror and consternation what's going on in the United States," he said finally.

Now "is a time to listen, it is a time to pull people together and a time to learn what injustices continue despite progress over years and decades," he added.

Trudeau was responding to a CBC reporter who also asked the prime minister for his views on police using tear gas to clear protesters from outside the White House so Trump could pose for photographs at a nearby church damaged during civil unrest, and why Trudeau at times seemed reluctant to criticize Trump.

Usually quick on his feet, Trudeau's pregnant pause during his daily COVID-19 briefing, televised live nationwide, spoke loudly.

The two leaders have had a rocky relationship since Trump walked out of a G7 summit in Quebec in June 2018, but they appeared to have mended fences last year at the conclusion of North American free trade negotiations.

As he has done in recent days, Trudeau chose to focus on Canada in his answer and reaffirmed that there was still a lot to do to fight racism in this country. 

He also cautioned against drawing comparisons between Canada and the United States, or concluding "that we are much better here."

"Canadians [must] recognize that we too have our challenges, that black Canadians and racialized Canadians face discrimination as a lived reality every single day," he said.

"We need to see that not just as a government and take action, but we need to see that as Canadians. We need to be allies in the fight against discrimination."