New Prime Minister Mark Carney has promised to oversee the biggest transformation of Canada's economy since the end of World War II to enable it to "stand up" to Donald Trump.

Carney led the Liberal Party to a dramatic fourth mandate in elections on Monday after a campaign focused on the US president's threats to Canada's economy and sovereignty.

Liberals fell just short of the 172 seats needed for majority control of parliament, but with 169 confirmed wins they will be in a strong position to pass legislation. Recounts in two closely contested electoral districts saw the party lose a seat in Quebec province but gain another in Ontario.

At his first press conference since his victory, Carney struck a determined note.

Known for weighing his words carefully, he said that he was "in politics to do great things, not to be something".

Canada's strained relations with the United States was among his "immediate priorities," he said, announcing a trip to Washington on Tuesday to meet with Trump on trade and security issues.

Canadians elected him "to stand up to President Trump," he said, adding that he will act "with focus and determination."

"Our focus will be on both immediate trade pressures and the broader future economic and security relationship between our two sovereign nations," said Carney.

But he warned also not to expect any "white smoke" from their first meeting signaling a sudden breakthrough.

Carney reiterated his message from the campaign that he believes the old relationship between the neighbors "based on steadily increasing integration is over."

"The questions now are how our nations will cooperate in the future," he said.

Trump "respects strength," Carney added, explaining that this was why he was preparing the country for major changes including a massive build-up of infrastructure and new housing.

Carney, who previously headed the Bank of Canada and the Bank of England, promised to maintain counter-tariffs on American products as long as Washington's measures were in place.

"This will be an incredibly exciting time as we take control of our economic destiny to create a new Canadian economy," Carney said.

To this end, he promised to abolish existing trade barriers between Canadian provinces by July 1 to expand the economy, and to strengthen trade with "reliable allies."

"Canada has what the world needs, and we uphold the values the world respects," he said. (AFP)