Federal Aviation Administration officials on Friday urged Congress to approve government funding as more air traffic controllers call in sick amid the shutdown.

Nearly 50% of 30 busiest airports facing absences as staff are forced to work without pay and shutdown hits 31st day

"After 31 days without pay, air traffic controllers are under immense stress and fatigue," the Federal Aviation Administration warned.

Federal Aviation Administration officials on Friday urged Congress to approve government funding as more air traffic controllers call in sick amid the shutdown.

Half of major US airports are experiencing staff shortages and delays.

Absences surge among US air traffic controllers, who have been working for more than a month without pay.