“This is the Trump administration making a political move to put pressure on Democrats to support their budget priorities of slashing health care and nutrition programs,” Representative Steve Cohen of Tennessee, the top Democrat on the House aviation oversight subcommittee, said in a statement on Thursday.

But for passengers, Thursday was spent in limbo, checking and rechecking whether their flights would be among the ones canceled starting Friday morning. The federal agencies that would be carrying out US flight cuts staffing at airports, the Transportation Department and the Federal Aviation Administration, were largely quiet throughout the day.

By that point, airlines, industry groups and even some news organizations had already been warning airports and passengers based on their own understanding of how government silence on flight cuts were expected to impact operations.

The long period of silence from the administration also did nothing to calm travelers’ fears. They found themselves repeatedly checking flight details, while airports officials anxiously awaited word on how their operations would be affected.

But in the statement that came along with the release of the government flight delays, Mr. Duffy said the decision — which airline experts have said was highly unusual in the airline industry — was not made on political grounds.

“This is about reviewing the data and reducing growing risks in the system while air traffic controllers continue to work without pay,” he said.

In the final hours, airline operations affected to be in good spirits, with experts saying the major carriers were expected to face only minor disruption. But that fed into complaints by administration critics that it proved their view that Wednesday’s announcement was intentionally done for optics over operational need.