"This is about where’s the pressure and how do we alleviate the pressure," Transportation Secretary Sean Duffy said.

He also said that even if the government shutdown ends, flights won't return to normal instantly, as it will take time to restore staffing levels and schedules. Load any apps related to your airline or airport onto your phone -- they can send you information about delays and cancellations.

More than 1,000 flights have been canceled and at least 5,000 delayed today, mostly due to a combination of air traffic controller staffing issues and an FAA-mandated 4% cut to flights because of the government shutdown.

U.S. airlines began canceling hundreds of flights Thursday due to the Federal Aviation Administration’s order to reduce traffic at the country’s busiest airports starting Friday because of the government shutdown.

Airlines canceled a dozen flights to and from Portland International Airport on Friday as federal flight safety regulators ordered reductions amid the historic government shutdown. The cancelations represent less than 3% of all the flights in and out of PDX scheduled Friday,

As the government shutdown continues, more challenges await passengers as they deal with the newest announcement from the Trump administration: a 10 percent cut in flights at 40 U.S. airports.

The FAA will reduce air traffic at 40 airports beginning Friday. Philadelphia International Airport is among those expecting flight cuts and delays. Talks between Democrats and Republicans to end the shutdown are intensifying,

Passengers on flights canceled due to the FAA order are entitled to a refund from the airline. While Knoxville's airport is not on the reduction list, travelers to and from 40 major hubs could be affected.