Close to 500 flights scheduled for Friday were already cut nationwide, and the number of cancellations climbed steadily throughout Thursday afternoon, according to FlightAware, a website that tracks flight disruptions

The FAA order to cut flights at 40 of the busiest airports across the US includes New York, Los Angeles and Chicago, but the impact will disrupt travel at many smaller airports, too

The FAA seeks to reduce service by 10 per cent across "high-volume" markets to maintain travel safety as air traffic controllers exhibit signs of strain during the shutdown. The move also comes as the Trump administration is ramping up pressure on Democrats in Congress to end the shutdown

Airlines will phase in the 10 per cent reduction in their flight schedules at the airports across more than two dozen states. Just hours before the reductions went into place, airlines were scrambling to figure out where to cut and some travellers began changing or cancelling itineraries preemptively

Travellers with plans for the weekend and beyond waited nervously to see if their flights would take off as scheduled