The Federal Emergency Management Agency and the Department of Homeland Security are conducting emergency response drills at MetLife Stadium in northern New Jersey to make sure the New York City area is prepared in the event of a nuclear attack.

Dubbed "Operation Gotham Shield," the simulation aims to determine how best to evaluate, treat and transport people who are injured in the event that a 10,000-ton improvised nuclear weapon is deployed on the New Jersey side of the Lincoln Tunnel, which connects the town of Weehawken to Midtown Manhattan.

Emergency management organizations in New Jersey and New York are also taking part in the drills, which will span several days and are being held about 15 minutes from Manhattan in the city of East Rutherford.

"Today’s large scale exercise focused on multiple emergency response agencies coming together from multiple states for the purpose of drilling logistics and equipment resources, while working with each other within the framework of a large scale mass casualty event," the Morris County Office of Emergency Management wrote on Facebook. "In Morris County, we plan for the worst and hope for the best. We pride ourselves on our capability to respond to the worst case scenario, and today’s exercise provided a framework for dealing with the type of event we hope we never experience."

A large-scale medical reception area was staged outside the stadium by the New Jersey EMS Task Force, including a mobile emergency room and dozens of ambulances.

Similar exercises have taken place in New York’s capital, Albany, as well as Washington, DC, and other places across the northeastern US. Authorities say that threats from North Korea and other international incidents did not prompt the drills.

Describing the mobile emergency room, Dr. Herman Morchel from the Hackensack University Medical Center told New York’s Pix 11 Tuesday that, "It’s basically a 48-foot or so tractor trailer … Once it's closed up, we can drive anywhere. And if we're on scene, I'd say within 30 to 45 minutes we would be open and seeing patients."

He added that in the event of a nuclear attack, every patient would be evaluated for radiation.

Washington’s "full scale" drill "to prepare for the possibility of a complex coordinated terror attack in the National Capital Region," began on Wednesday as a rare full Senate briefing on North Korea was underway.