Canada will soon require that air travelers test negative for COVID-19 before arrival, federal ministers said on Wednesday, after social media images of maskless tourists prompted a call for stricter measures to curb the virus.

“Canada will quickly implement the requirement for all arriving passengers to have a negative PCR COVID test three days before arriving in Canada,” said Dominic LeBlanc, intergovernmental affairs minister, at a media briefing.

Bill Blair, minister of public safety, later said the new requirement would apply to air passengers, while the federal government is working with provinces on how to supplement strong measures with additional testing at Canada’s land borders. He said the federal government will discuss the measure with the airline industry and share more details soon.

Canada reported a total of 565,506 cases of COVID-19 as of Wednesday, 6,442 more than the day before, as new cases surged across western Canada, Ontario and Quebec.

The pre-boarding testing will not eliminate the requirement for people arriving in the country to quarantine for 14 days, Blair said.

“We strongly advise against all discretionary travel,” said Blair, while noting that Canadian governments cannot stop citizens who choose to travel from returning home. Travelers who break quarantine face up to six months in jail or up to C$750,000 in fines.

On Tuesday, Quebec urged the federal government to require COVID-19 testing for residents returning from year-end vacations.

Canada’s travel restrictions are among the world’s toughest, with non-essential foreigners normally denied entry and citizens returning from abroad mandated to quarantine.