After scrambling to address the Federal Aviation Administration request on Wednesday to reduce air traffic by 10%, United Airlines, which has a hub at Denver International Airport, said Thursday that they’ve canceled 4% of flights through Sunday, “as per guidance from the FAA” through the weekend, said spokesperson Russell Carlton.

More flight cancellations are expected at Denver International, which is among 40 total airports impacted nationwide this weekend.

United operates its largest hub at Denver International Airport and confirmed that reductions affect flights scheduled for Friday, Nov. 7, through Sunday, Nov. 9.

Regional routes to smaller markets are most likely to get cut to meet the FAA’s request to reduce commercial flights by 10 percent.

More than 70 flights to and from Denver International Airport were canceled Friday as the Federal Aviation Administration ’s unprecedented order to scale back flights nationwide because of the record-long government shutdown took effect.

United Airlines cancelled 21 flights at DIA Friday, representing about 4% of its scheduled departures, as part of an FAA-mandated slowdown designed to address air traffic controll

United will be reducing flight schedules during the shutdown as the Federal Aviation Administration looks to maintain safety across the country as many of their workers remain in furlough.

According to the FAA, thousands of flights at "high-traffic" airports across the country will be cut or canceled starting Friday. The decision, the FAA and U.S. Transportation Secretary Sean Duffy said, was based on where air traffic controllers are feeling the most pressure.

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.