Prime Minister Justin Trudeau says Ukraine should be allowed to strike deep inside Russia, despite Moscow threatening that this would draw Canada and its allies into direct war.

"Canada fully supports Ukraine using long-range weaponry to prevent and interdict Russia's continued ability to degrade Ukrainian civilian infrastructure, and mostly to kill innocent civilians in their unjust war," Trudeau told reporters at a news conference in Ste-Anne-de-Bellevue, Que., on Friday.

On Thursday, Russian President Vladimir Putin warned that the NATO military alliance allowing Ukraine to use weapons it has provided for long-range strikes "would mean that NATO countries, the United States and European countries, are at war with Russia."

Ukraine and many of its supporters want U.S. President Joe Biden to let Kyiv use the weapons to strike military targets deeper inside Russia.

Trudeau said Ukraine can use this capacity to stop Russia's frequent strikes on hospitals and daycares across the country.

Putin's remarks were in line with the narrative the Kremlin has promoted since early in the war, accusing NATO countries of de facto participation in the conflict and threatening a response.

His comments came five weeks after Ukrainian forces stormed the border and put parts of Russian territory under foreign occupation for the first time since the Second World War.

Trudeau told reporters on Friday that Canada is "unequivocal" that Ukraine must win in fighting back against Russia's invasion, or it will encourage other large countries to try absorbing their neighbours. He said Putin's actions have consequences for everyone.

"He is trying to deeply destabilize the international rules-based order that protects us all, not just in every democracy around the world, but in all countries around the world," Trudeau said.

Biden had said on Tuesday that his administration was considering the issue and "working that out." The issue was also on the agenda Friday as Biden welcomed U.K. Prime Minister Keir Starmer to the White House.

Yet the White House's national security communications adviser, John Kirby, said the U.S. doesn't plan to stray from its policy. 

"There is no change to our view on the provision of long-range strike capabilities for Ukraine to use inside Russia," Kirby told reporters, adding he wouldn’t expect any major announcement in that regard coming out of Friday's discussions, "certainly not out of our side."

As for whether the long-range missiles are a red line for Putin, Kirby also said it’s difficult to take the Russian president at face value, though he added that Putin has proven capable of aggression and escalation.

In May, Washington began allowing Ukraine to use American weaponry to strike inside Russia, but only for targets near the border being used to attack Ukraine’s second-largest city, Kharkiv, which is 20 kilometres from the Russian border.

This report by The Canadian Press was first published Sept. 13, 2024.

— With files from Kelly Geraldine Malone in Washington and The Associated Press.