United Airlines has halted flights at major airports across the US over a “technology issue”, according to the company.

A ground stop was issued for the company’s mainline flights from departure airports, causing issues at airports including Chicago, Denver, Houston, San Francisco and New Jersey, the US Federal Aviation Administration’s website shows.

“We expect additional flight delays this evening as we work through this issue,” United told the BBC’s US partner CBS News.

“Safety is our top priority, and we’ll work with our customers to get them to their destinations,” the company said.

The BBC has contacted United Airlines for comment.

Flights that are already in the air will continue to their destination, the company told CBS News. It added that regional flights were not impacted but could be delayed because of traffic jams from the ground stops.

Over 700 United flights had been delayed as of 21:00 EDT (2:00 BST), according to flight tracking site FlightAware.