The partial US government shutdown is beginning to affect air travel, American news outlets have widely reported.
Travellers have been experiencing even longer queues than normal at some US airports, seemingly caused by a shortage of security officials many of whom are staying away due to not getting paid.
Aviation safety inspectors have also been reportedly staying away from their jobs.
A Federal Aviation Administration (FAA) spokesman said, however, that inspecting airline fleets was a priority under the circumstances.
About 10,000 air traffic controllers who work for the Federal Aviation Administration and about 51,000 Transportation Security Administration officers have been told to keep reporting to work because they are deemed essential.
Those workers at airport checkpoints, control towers and FAA radar stations aren’t being paid.
If the shutdown continues, food stamp recipients are likely to begin going without aid.
President Trump is due to address the nation in a televised speech in an attempt to win public and congressional approval for funding for his signature policy of building a wall on the Mexican border.
To date lawmakers have rejected his demands for up to US$5.7bn to build the project.
The government shutdown, as of 8 January, had entered its 18th day.