The Canadian government warns residents to avoid nonessential travel outside the country.

For travelers from Canada who are unclear what to do about holiday plans in international destinations, the federal government issued new guidance on Wednesday that could tip the scales: Consider canceling your trip.

Since early November, Canada has seen a steady rebound in coronavirus cases, according to a Dec. 10 epidemiology report published by the country’s public health agency. Now, with the rise of the Omicron variant — which spurred travel restrictions around the globe connected to several countries in southern Africa — the Canadian government has issued an advisory against all nonessential travel just over a week before Christmas.

“To those who were planning to travel, I say very clearly, now is not the time to travel,” the country’s health minister, Jean-Yves Duclos, said at a news conference on Wednesday afternoon.

The advisory will be in effect for four weeks and will then be re-evaluated. The government also plans to increase testing at the border, Mr. Duclos said, and will provide more detail in future announcements.

The Dec. 10 epidemiology report also shows that fewer than 1 percent of Covid-19 infections were contracted during international travel and that fewer than 1 percent were linked to an exposure to someone who had traveled.

Yet Mr. Duclos said avoiding travel was smart because Canadians abroad may not be able to gain access to health care if they get sick during travel.

“The situation abroad is already dire in many places,” Mr. Duclos said. “Once they have left Canada, there is very little we can do to help them.”

Fully vaccinated Canadians traveling by air or land for less than 72 hours will still be able to return home without providing proof of a negative coronavirus test, the country’s transportation minister, Omar Alghabra, said.

Over 76 percent of Canadians are fully vaccinated, according to federal data, with unvaccinated patients accounting for more than three-quarters of hospitalizations and deaths reported to the public health agency as of November.

As the holidays near, the country’s most populated province, Ontario, is recommending that personal gatherings be limited to 25 people as cases mount, fueled in part by the spread of new variants, including Omicron, which is estimated to infect 7.7 times as many people as the Delta variant, provincial health experts reported.

Provinces are racing to offer booster doses and free rapid antigen tests to Canadians through the holiday season, with an inventory of 16 million booster doses currently available and 35 million rapid tests scheduled for distribution by the federal government.