Air Canada began canceling flights Thursday ahead of a possible strike by its flight attendants that could impact hundreds of thousands of travelers. A complete shutdown of the country's largest airline threatens to impact about 130,000 people a day.

About 200 Air Canada flights are to the U.S., according to The Wall Street Journal. The strike comes as Canadians increasingly avoid the United States because of diplomatic tensions between the neighbors. With more Canadians taking vacations at home, Air Canada has seen extra pressure on domestic routes.