OTTAWA: Canada's Chrystia Freeland will no longer be in charge of spearheading diplomatic relations with the United States now that she is the new finance minister, three government sources told Reuters on Wednesday.

Prime Minister Justin Trudeau had made Freeland his main US go-between when he named her deputy prime minister after last year's election, with Foreign Minister Francois-Philippe Champagne handling all the other diplomatic files.

Now Champagne will also handle US ties, sources said.

"We're back in more of a traditional setup in terms of the relationship," said one of the sources. "Obviously with any relationship as complex as the Canadian-US one, by necessity, different ministers will be speaking to their counterparts."

As foreign minister in Trudeau's previous government, Freeland had led Canada's hard-nosed renegotiation of a new North American trade deal, known as the United States-Mexico-Canada Agreement (USMCA).

Because of the long shared border and close economic ties, the United States is by far Canada's most crucial ally, and the relationship was often strained during the trade negotiations and a dispute over aluminum tariffs.

In September of 2018, President Donald Trump hinted he did not like Freeland, without naming her.

"We're very unhappy with the negotiations and the negotiating style of Canada. We don't like their representative very much," Trump said.

Freeland will continue to support the prime minister in managing the US relationship, a third government official said, "particularly in the fight against the unfair and unjust US aluminum tariffs".

Tensions erupted again earlier this month when Trump moved to reimpose 10% tariffs on some aluminum products, prompting Freeland to respond the next day with retaliatory tariffs.

Canada has not yet officially informed the United States of the change in Freeland's responsibilities, a source familiar with the matter said.

"The most significant relationship we have with the United States is an economic one ... so she's still going to very much be there" as finance minister, said Stephanie Carvin, an assistant professor of international relations Ottawa's Carleton University.