Canada will provide another $500 million in military assistance to Ukraine as Prime Minister Justin Trudeau is set have a one-on-one discussion with President Volodymyr Zelenskyy at the NATO summit in Washington, D.C.

A senior government official speaking on background said Canada will also begin to provide much of Ukraine's fighter jet pilot training.

Trudeau has been forceful in conversations with NATO allies about the need to stay resolute in their support as the war-ravaged country takes top billing at the three-day summit.

But Trudeau has also been facing pressure from American politicians who are publicly critical of Canada for falling short of its defence spending commitments.

NATO allies have agreed to spend at least the equivalent of two per cent of their national gross domestic product on defence. Canada's current spend is around 1.37 per cent.

Trudeau tried to get ahead of the criticism during a speech Tuesday in which he said the Liberal government has been following through on promises to drastically increase defence spending since it came into power.

Since 2014, Canada's defence budget has grown by more than 57 per cent, and it is estimated at $29.9 billion for this year.

The only NATO countries that spend more in terms of real dollars are the U.S., United Kingdom, France, Germany, Italy, Poland and Turkey.

But 23 of the 32 allies are expected to meet the two per cent target this year, and Canada is the only one that hasn't presented a plan to get to that minimum.

Fen Hampson, a professor of international affairs at Carleton University in Ottawa, said the plan should have been shared earlier, "so our partners know we are serious."

"We are clearly in the bull's-eye of American politicians and the narrative is we are the weak northern link in NATO."

In May, 23 U.S. senators wrote Trudeau a letter urging him to come to the summit with a clear plan.

Senate Minority Leader Mitch McConnell pointed to Canada's spending failures following a meeting with Trudeau on Tuesday, and Mike Johnson, the Republican Speaker of the House of Representatives, was also critical during a talk at the Hudson Institute in Washington the same day.

"Talk about riding on America's coattails," Johnson said. "They have the safety and security of being on our border and not having to worry about that. Talk about shameful."

Defence Minister Bill Blair suggested earlier this week in Washington that he was bringing to the summit the kind of plan allies have been asking for.

The Canadian government pushed back on concerns by announcing an incremental move toward replacing its fleet of submarines Wednesday.

Blair said Canada will buy up to 12 conventionally powered, under-ice capable submarines — something the government pledged to do in its new defence policy in April.

The announcement did not include a cost estimate that would clarify for allies or Canadians how much the project will help in closing the two per cent gap.

The government official said more information about Canada's plan to get to the target would be shared Thursday.

In the morning, Trudeau met with new Dutch Prime Minister Dick Schoof and with South Korean President Yoon Suk Yeol, who is not a NATO leader but is taking part in the alliance's Indo-Pacific working groups.

The Canadian official said submarines were talked about in the meetings.

The prime minister is later set to join other NATO leaders for a dinner hosted by U.S. President Joe Biden at the White House.

Concerns over Biden's health and the possibility of a second Donald Trump presidency have already cast a shadow over the summit.

Trudeau wouldn't respond Tuesday when a reporter asked him if he had concerns about the 81-year-old's age or mental acuity.

But Polish President Andrzej Duda brushed aside questions about the American president on Wednesday, saying he met with Biden "and there is no doubt that everything is OK."

"We don't need to interfere in the American election," Duda said at the summit.

The U.S. president has been under international scrutiny after a disastrous debate performance last month against Trump.

Biden delivered a clear and forceful speech at NATO's 75th anniversary celebration Tuesday evening at a critical time for the Democratic leader and for stability in his party.

The president made a brief statement, looking down at times as he referenced his remarks, as the demands of the summit continued Wednesday.

Biden's team has said the president is sharpest earlier in the day and tries to avoid events after 8 p.m. That's the time Wednesday's dinner with the NATO leaders was set to begin.

This report by The Canadian Press was first published July 10, 2024.

— With files from Sarah Ritchie in Ottawa.