NEWARK, NEW JERSEY - NOVEMBER 30: United Airlines planes sit on the runway at Newark Liberty International Airport on November 30, 2021 in Newark, New Jersey. The United States, and a growing list of other countries, has restricted flights from southern African countries due to the detection of the COVID-19 Omicron variant last week in South Africa. Stocks in the travel and airline industry have fallen in recent days as fears grow over the spread and severity of the variant.  (Photo by Spencer Platt/Getty Images)
CNN  — 

Citing air traffic congestion, United Airlines said Thursday it will cut 12% of its daily domestic flights from its busy Newark hub.

The cuts start in July and amount to about 50 daily flights.

Newark is a critical New York-area junction in United’s flight network and has consistently been among the US airports with the most delays and cancellations.

Executive Jon Roitman wrote in a message to employees shared with CNN that the schedule changes “should help minimize excessive delays and improve on-time performance – not only for our customers, but for everyone flying through Newark.”

United CEO Scott Kirby recently told CNN’s Richard Quest, “the biggest issue is, there’s more flights scheduled in Newark, for example, than there is capacity at the airport, even on a perfect blue sky day and air traffic control is understaffed and because of that, there is just more flights than the airport can handle.”

United is currently in a blame battle with several airlines, including Spirit, over congestion at the airport. United claimed in a May letter to the FAA that the other carriers are “creating a crisis at EWR” by scheduling too many peak-hour flights.

Spirit responded with the assertion that United holds “virtual monopoly status at Newark.”

The Federal Aviation Administration does not control takeoff and landing slots at Newark to the extent it does at some of the nation’s other most congested airports. United said it received a waiver from the FAA “for the remainder of the summer” to protect its future rights at the airport.

In a statement, the agency said: “The FAA has allowed United Airlines to not use some of its slots at Newark Liberty International Airport (EWR) due to construction at several gates and runway construction.”

United said it has the staffing to support its schedule and plans to “revert to a full schedule from Newark as soon as possible.”

United is the latest among several US carriers trimming their summer schedules. Last month, Delta Air Lines announced it would cut 100 flights a day from its schedule this summer. JetBlue Airways and Alaska Airlines have also reduced flights.

Concern over air travel chaos has been mounting with the rise in demand this summer.

Transportation Secretary Pete Buttigieg recently urged airline executives in a private conversation to review their flight schedules and take other steps to soften the impact of summer flight cancellations.

CNN’s Pete Muntean contributed to this report.

Top image: United Airlines planes sit on the runway at Newark Liberty International Airport in Newark, New Jersey, in this November 30, 2021, file photo. (Spencer Platt/Getty Images)