Prime Minister Justin Trudeau, giving a rare insight into his future plans, said he wanted to serve Canadians for a number of years to come, and shied away from saying who he thought should succeed him.

Trudeau, speaking at the Reuters Next conference, also said he was opposed to the idea of obliging people to carry digital proof that they had been vaccinated against COVID-19.

Trudeau's ruling Liberals only have a minority in the House of Commons, which means he relies on the opposition to govern and can be brought down at any time.

Senior Liberals say they expect an election some time this year, and some privately question how much longer he might want to stay in power.

Trudeau, 49, has three school-age children. He first took over as prime minister in November 2015 and has at times appeared tired amid the relentless COVID-19 crisis. He admitted dealing with the pandemic had been hard, but made clear he had no plans to quit soon.

"I've still got a lot to do in terms of serving this country, so I'm looking forward to a number of more years of serving Canadians," he said in an interview aired on Thursday.

The comments were the clearest signal he has given that his political ambitions are far from exhausted.

Trudeau came to power promising to focus on causes such as feminism and the environment. But he quickly found himself having to deal with issues such as how to handle U.S. President Donald Trump and then the pandemic.

He has come to rely heavily on Chrystia Freeland, a close ally, who now occupies the positions of both finance minister and deputy prime minister. Liberal insiders say this would give her an advantage in a future leadership race.

Asked whether Freeland might one day become Liberal leader, Trudeau replied: "My responsibility is to bring around me the best possible team I can to serve Canadians ... I won't speculate on what could happen years down the road."

The Liberal government has spent more than C$200 billion in direct aid to help people and businesses survive the pandemic and Trudeau reiterated Ottawa planned to spend another C$100 billion over the next few years to kick-start an economic recovery.

But he made clear he opposed a vaccine passport for people who had received inoculations, an idea already being developed in Denmark, saying it was fraught with challenges.

"I think the indications that the vast majority of Canadians are looking to be vaccinated will get us to a good place without having to take more extreme measures that could have real divisive impacts on community and country," he said.

(Writing by David Ljunggren, Editing by Nick Zieminski)