Russian airliners continue to fly through Canadian skies after several European countries shut their airspace to Russian carriers in response to Moscow’s invasion of Ukraine – but Ottawa is keeping all options on the table.

Transport Minister Omar Alghabra says in a statement that Canada’s airspace remains open to Russian airlines “at this time,” but that the department is actively monitoring the situation and working with the United States and other key allies.

Russia’s flagship carrier Aeroflot operates multiple flights per day through Canadian airspace en route to the United States and beyond.

Aerospace consultant Ross Aimer says the passage marks a critical route for the airline, and that Russia would almost certainly retaliate to flyover bans in kind.

On Thursday, the United Kingdom suspended Aeroflot’s foreign carrier permit, with Poland, Bulgaria and the Czech Republic following suit by closing their airspace to Russian planes.

Launched this week, Russia’s large-scale invasion of Ukraine closed in on the capital of Kyiv on Saturday as troops struck the country from three sides.