Ottawa, Canada - Canada's new Prime Minister, Mark Carney, on Friday launched his term in office with a whole-hearted rejection of US President Donald Trump's repeated threats to annex his northern neighbor.

Shortly after he was sworn in as Canada's 24th prime minister, replacing Justin Trudeau who has been in office since 2015, Carney said confronting Trump's tariffs would be a top priority.

Canada "will never, ever, in any way, shape or form, be part of the United States," he said, while voicing hope his government could one day "work together" with Washington to advance each country's interests.

Ottawa has been rattled by collapsing cross-border relations since Trump returned to power in January, launching a trade war and demanding that Canada surrender its independence to become the 51st US state.

Canada Canada strikes back at Trump's tariffs with multi-billion dollar retaliation

Ottawa has retaliated against Trump's tariffs, while Canadian public opinion has been outraged as the US president insists the border separating the countries should be erased.

Carney has characterized the Trump administration as the greatest challenge Canada has faced in a generation.

He became prime minister after overwhelmingly winning a Liberal Party vote to replace Trudeau as leader, but the former central banker, who turns 60 on Sunday, is a political novice who has never won an elected public office.

Carney's campaign skills may be tested soon, with Canada likely headed for a general election in weeks.

He said he will fly to Paris and London next week, part of an effort to reinforce Canada's alliances overseas as ties with the US unravel.