TORONTO (AP) — Canada’s border agency is announcing stricter rules for Americans travelling through Canada to Alaska amid the pandemic.

The Canada Border Services Agency says the rearview mirror of cars will be marked with a leave-by date while they are in Canada en route to or from Alaska.

The U.S. Canada border remains closed to all non-essential travel but Americans and foreigners can drive to and from Alaska provided they follow certain rules.

Some Americans had been visiting popular tourist destinations in Canada, such as Banff National Park, after telling border agents they were driving to Alaska.