The Federal Aviation Administration halted flights into New York’s LaGuardia Airport because of a shortage of air-traffic control staff, escalating the pressure on President Donald Trump and lawmakers to end the government shutdown.

A lack of workers at an air-traffic control facility in the Washington area prompted the FAA to order a ground stop at LaGuardia, one of the nation’s busiest transportation hubs. Flights at other East Coast airports such as Washington’s Reagan National, Newark Liberty International and Philadelphia International were also delayed Friday.

The flight disruptions underscored the rising impact of the government shutdown as the closing dragged into the 35th day. Top bosses of U.S. airlines warned of the risk to the aviation system Thursday, with JetBlue Airways Corp. Chief Executive Officer Robin Hayes saying the situation was reaching a “tipping point.”

A staffing shortage also was reported at a facility overseeing air traffic in Jacksonville, Florida, according to an FAA website.

This article was provided by Bloomberg News.