CHICAGO (Reuters) -United Airlines is facing a financial hit and potential long-term reputational harm as flight delays and cancellations pile up due to ongoing disruptions at Newark airport - one of its largest hubs and among the busiest in the country.

Newark airport is struggling with radar issues, staffing shortages and construction delays — and travel experts recommend alternative airports as passengers report significant flight disruptions.

The nation’s air traffic controllers union says the flight cancellations plaguing Newark Liberty International Airport in new Jersey and spilling over to U.S. airports can be traced to a week ago when controllers temporarily lost contact with planes.

United Airlines is providing fee waivers for passengers who experienced significant delays and cancellations at Newark Liberty International Airport.

Don't be surprised if the delays, cancellations and safety concerns that have affected Newark Liberty International Airport in recent weeks spread to the rest of the U.S. That's according to Transportation Secretary Sean Duffy, who on Sunday said "antiquated systems" at major airports across the country need a multibillion-dollar overhaul.

Flights in and out of Newark Liberty International "one hundred percent" need to be scaled back, Transportation Secretary Sean Duffy told NBC on Sunday morning - just as the glitch-plagued airport experienced another service outage over aging communications tech.

Newark airport's been plagued with issues that have travelers like me concerned about safety. It's not dangerous, but delays are a bigger concern.

Facing mounting flight disruptions at Newark Liberty International Airport, United Airlines is urging the Federal Aviation Administration to reinstate flight caps to alleviate congestion and improve safety.