Several flights departing from Montreal-Trudeau International Airport to the United States are cancelled after U.S. customs authorities temporarily suspend operations at the airport, according to multiple outlets. The airport says the disruption is caused by U.S. Customs at the Montreal facility and affects specific flights rather than all departures. The cancellations occur while the U.S. customs process is paused, limiting the ability for incoming and departing air travel to complete required procedures. The airport statement indicates the situation is tied directly to the temporary suspension of U.S. customs services, and that affected flights do not proceed as scheduled during the suspension period. Further details such as which specific airlines or destinations are impacted are not provided in the available excerpts. The reports focus on the operational impact at the airport and the role of U.S. customs in triggering the cancellations for flights bound for the United States.