The Federal Aviation Administration on Monday ordered ground stoppages at several major airports in the north-east due to equipment problems, affecting the plans of thousands of passengers.
It comes as New York prepares to host scores of world leaders this week for the UN General Assembly. Representatives of nearly 200 countries and territories will be arriving to lay out their nations' priorities for the coming year.
The FAA said it was pausing flights into Philadelphia International, Teterboro and Newark Liberty International airports due to issues with some frequencies at Philadelphia's Terminal Radar Approach Control, or Tracon.
The Tracon system manages planes in the airspace around major airports, guiding planes between the airport tower and en-route centres. It is unclear how long the stoppage will continue.
Dozens of planes idled on the runway, with delays of up to 150 minutes at major airports in Newark and Philadelphia.
Flightradar24, a flight-tracking website, said that planes at John F Kennedy and LaGuardia airports in New York had also been affected. The airports are two of the busiest in the country, with more than 2,000 total take-offs and landings a day.
The issue comes as the FAA rolled out its artificial intelligence-powered tool to manage flights for Washington-area airports.
Transportation Secretary Sean Duffy has described the tool as a solution for the country's air traffic control problems.
