The US Federal Aviation Administration on Friday ordered all flights across the United States to remain on the ground until further notice, citing extraordinary circumstances and safety concerns.
It said international flights bound for the US would be reviewed on a case-by-case basis.
The cause of the nationwide suspension was not immediately clear. However, CNN reported that an FAA spokesperson said a communications problem was affecting en-route air traffic control centres, which manage flights crossing the country.
Shortly before the nationwide order, the FAA had already halted all air traffic at Chicago airport because of communications problems within air traffic control.
The last time a nationwide ground stop was imposed in the US was in January 2023, when an outage hit the system used to send notices to pilots.
