According to The Hill, the ongoing government shutdown, now in its 20th day, has led to a significant shortage of air traffic controllers, resulting in widespread flight delays across the nation, as confirmed by the Federal Aviation Administration (FAA) on Monday.

FlightAware reported that on Sunday alone, approximately 7,850 flights within, into, or out of the United States experienced delays. By Monday, over 1,000 flights had already faced similar issues.

The FAA attributed weekend delays in major cities such as Atlanta, Chicago, Dallas, and Newark to staffing shortages, according to Reuters. The agency also warned of potential delays in Las Vegas and Phoenix due to the same reason.

An FAA spokesperson informed The Hill, “As [Transportation] Secretary [Sean] Duffy has mentioned, staffing shortages have increased across the system. When this occurs, the FAA reduces traffic flow into certain airports to maintain safety.”

In addition to staffing issues, Reuters noted that weather conditions and the Formula 1 event in Austin on Sunday also contributed to the delays.

Duffy said on Fox Business earlier this month that 53 percent of flight delays were caused by staffing issues, a stark comparison to the usual five percent.

Roughly 13,000 air traffic controllers and 50,000 Transportation Security Administration agents are working without pay through the shutdown.

Experts in recent days have warned of more flight delays as it is common for airport staff to take sick days when they are working without pay, as illustrated by the 2019 government shutdown. 

Throughout the shutdown, the Trump administration has aired videos in some airports placing blame on Democrats for not reopening the federal government. A lot of airports have refused to play these videos. 

The current shutdown is the third longest in American history.