Transportation Secretary Sean Duffy warned there will be a 10% reduction in air travel capacity at 40 major airports in the US starting Friday morning, if the government shutdown continues, BBC reported.

The decision was made because air traffic controllers have been reporting issues with fatigue, the head of the Federal Aviation Administration (FAA) said at a briefing with Duffy on Wednesday.

"It is unusual, just as the shutdown is unusual, just as the fact that our controllers haven't been paid for a month is unusual," said FAA chief Bryan Bedford, according to BBC.