Canada's population has reached more than 40 million, Statistics Canada said. 

The milestone comes amid a wave of new immigrants as part of Ottawa's promise to bring in 500,000 people a year by 2025. 

The 40-million mark came faster than expected, Statistics Canada said, as the country added 1.1 million people in 2022, most of them permanent and temporary immigrants. 

That's more than twice the federal government's plan to welcome more than 430,000 new permanent residents last year. 

Last year was the first year Canada's population grew by more than a million people in a 12-month period, Statistics Canada said, with 95.9 per cent of that growth through international migration. 

Canada's population passed 30 million in 1997, also amid increasing immigration levels. 

By comparison, the U.S. population is around 335 million. 

Statistics Canada said that if current immigration levels remain, Canada's population could hit 50 million in two decades. And by 2041, two in five Canadians could be born abroad. 

Ontario is Canada's most populous province with almost 15.6 million people, while Quebec comes a distant second at 8.8 million.

Michael Donnelly, a political science professor at the University of Toronto, said immigration is imperative to Canada for a number of reasons, including the need to increase the working population. 

"The people who are working today are paying for the pensions of people retired today," he said. Canada needs newcomers who will fill labour shortages, contribute to the economy and Canada's public pension program. 

But a growing population also brings challenges when it comes to infrastructure and housing. Last year, the Canada Mortgage and Housing Corporation (CMHC) said the country needed to build 3.5 million more homes than it is on track for in order to restore housing affordability.

"In effect we don't have enough housing for all the demand, and we need to add a lot more," said Nathanael Lauster, a sociology professor at the University of British Columbia who studies population and demographics. 

Lauster said immigration can actually help alleviate the issue because "one of multiple constraints holding housing back is labour supply."

This report by The Canadian Press was first published June 16, 2023.