The two leaders met while Zelensky was in Toronto on his first visit to North America to participate in a conference on Ukrainian reforms.

"In the wake of Russian aggression and attempts to undermine Ukraine's sovereignty, including the illegal annexation of Crimea, it's all the more important for countries like Canada to stand alongside its partner," said Trudeau during a press conference with the newly-inducted Ukrainian president.

"Russia's actions are not only a threat to Ukraine but to international law," Trudeau said.

The conference, which ends Thursday, brings together representatives from 30 countries, the European Union, and international organizations such as the International Monetary Fund, the World Bank and NATO.

Trudeau added he was "dismayed" that Russia was reinstated in the Parliamentary Assembly of the Council of Europe (PACE), after the country was stripped of its voting rights in the pan-European rights body in 2014 after the annexation of Crimea.

Trudeau noted that the reinstatement came despite Russia "having not liberated the Ukrainian sailors" detained in the country since November 2018, as well as three Ukrainian naval vessels, which were seized in the Kerch Strait at the same time.

Zelensky said he was "disappointed" by the Council's decision. In protest, Ukraine announced Tuesday it was withdrawing its invitation to PACE monitors to observe parliamentary elections to be held on July 21.

Trudeau and Zelensky also discussed Canadian arms sales and Canada's military training mission in Ukraine.

In March, Ottawa renewed its mission of some 200 Canadian troops deployed to Ukraine until the end of March 2022.

Since 2015, Canada has so far trained nearly 11,000 Ukrainian soldiers.

Regarding Ukrainian reforms, Trudeau said there has been "much improvement" in the last few years, which he believes will continue, particularly in the fight against corruption.

The Canadian leader said he is convinced that with the election of Zelensky, a former comedian who took office in May, there will be "even more positive steps" in Ukraine.

"We will be patient because there is a lot of work to do," Trudeau said.

Foreign Minister Chrystia Freeland also announced $45 million in additional Canadian assistance to Ukraine in support of its reforms and a proposed national police force.

Since 2014, Canada -- the first Western country to recognize Ukraine's independence in December 1991 and home to a large Ukrainian diaspora -- has provided the country more than $785 million in aid.

Freeland also condemned Russia's decision to issue Russian passports to Ukrainian citizens in the Donbass region, a disputed area in eastern Ukraine that is a hotbed of pro-Russian separatism.

"Starting today, Canada will take action to ensure that these passports cannot be used to travel to Canada. We encourage our partners to do likewise," she said.

The armed conflict between Ukrainian forces and the pro-Russian separatists has claimed 13,000 lives since 2014.