The Department of Transportation may close some parts of the airspace if enough air traffic controllers don’t show up to work, Transportation Secretary Sean Duffy said Tuesday.

With flight delays on the rise nationwide, Transportation Secretary Sean Duffy cautions that the situation may get worse the longer the government shutdown continues.

Transportation Secretary Sean Duffy warned that certain parts of the U.S. airspace may close next week if the federal government shutdown continues. The warning comes as the country reaches the longest shutdown in history.

Airports across the country have already seen delays and cancellations due to staffing shortages as the shutdown continues.

Senate Democrats have voted 13 times against a stopgap measure funding the government at current levels until Nov. 21.

Transportation Secretary Sean Duffy warned of "mass chaos" for air travel if the longest shutdown on record drags on.

Belgium will work to improve surveillance of its airspace following repeated sightings of drones over its airports and military bases, Defence Minister Theo Francken said on Thursday. Belgium's Brussels and Liege airports were closed for hours on Tuesday evening after drone sightings,

Several airlines are offering the option to rebook or issue a refund for customers whose flights are impacted by the reductions.