Air travel turmoil deepened with more than 4,300 flights delayed nationwide on Monday following more than 8,800 delays on Sunday, with air traffic controller absences surging as the federal government shutdown reached its 27th day.

The Federal Aviation Administration cited staffing shortages affecting flights across the Southeast and at Newark Airport in New Jersey, while the agency imposed a ground stop at Austin Airport in Texas and a ground delay programme at Dallas Fort Worth International Airport that delayed flights by an average of 18 minutes.

Southwest Airlines had 47 per cent, or 2,089, of its flights delayed on Sunday, while American Airlines had 1,277, or 36 per cent, of its flights delayed, according to FlightAware, a flight-tracking website. United Airlines had 27 per cent, or 807, of its flights delayed and Delta Air Lines had 21 per cent, or 725, of its flights delayed.

Roughly 13,000 air traffic controllers and 50,000 Transportation Security Administration (TSA) officers must work without pay. The Trump administration has warned that flight disruptions will increase as controllers miss their first full pay cheque on Tuesday.

On Monday, Southwest had 24 per cent of flights delayed, American 18 per cent and Delta 13 per cent, according to FlightAware.

A US Transport Department official said 44 per cent of Sunday’s delays stemmed from controller absences – up sharply from the usual 5 per cent.