An official says Canadian Prime Minister Trudeau is set to resign as Liberal Party leader, effectively ending nearly a decade in power.

The official said that Trudeau will stay on as prime minister until a new party leader is chosen. The officials spoke on condition of anonymity because he was not authorized to speak ahead of an official announcement Monday.

It is not clear when nationwide elections would be held to pick a permanent replacement.

Here's the latest:

Trudeau came to power in 2015 after 10 years of Conservative Party rule, and had initially been praised for returning the country to its liberal past. But the 53-year-old leader, the son of Pierre Trudeau, one of Canada’s most famous prime ministers, became deeply unpopular with voters in recent years over a range of issues, including the soaring cost of food and housing, and surging immigration.

The political upheaval comes at a difficult moment for Canada internationally. U.S. President-elect Donald Trump has threatened to impose 25% tariffs on all Canadian goods if the government does not stem what Trump calls a flow of migrants and drugs in the U.S.

That's even though far fewer of each crosses into the U.S. from Canada than from Mexico, which Trump has also threatened.