Canadian Prime Minister Justin Trudeau said his priority in talks with King Charles on Monday will be protecting his country's sovereignty after U.S. President Donald Trump recently suggested making Canada the 51st U.S. state.

Trudeau said nothing is more important to his citizens than "standing up for our sovereignty and our independence", ahead of the meeting with Charles, who is Canada's head of state.

Last week, Charles invited Trump to what would be a historic second state visit to Britain, with Prime Minister Keir Starmer handing over the invitation during a meeting before the world's media in the Oval Office.

"I look forward to sitting down with His Majesty tomorrow, as always we will discuss matters of importance to Canada and Canadians, and I can tell you that nothing seems more important to Canadians than standing up for our sovereignty and our independence as a nation," Trudeau told reporters.

Trudeau, the outgoing prime minister, said last month that Trump's talk about absorbing Canada "is a real thing" and is linked to the country's rich natural resources.

Trump has repeatedly suggested Canada would be better off if it agreed to become the 51st U.S. state.

Trudeau was also asked about Trump's meeting with Ukrainian President Volodymyr Zelenskiy. "I stand with Zelenskiy," he said.