The Covid-19 surge is beginning in northern New Jersey, Department of Health Commissioner Judith Persichilli said.
Some hospitals in the northern part of the state have asked ambulances to not bring patients to the hospital. Two hospitals called to say they needed ventilators, Persichilli said.
Officials are looking at possible alternative sites, Persichilli said.
The field hospital will begin being staffed next week, she said.
At least 93 of the long-term facilities across New Jersey are reporting at least one positive Covid-19 case, she said.
About 5,200 healthcare professionals have volunteered to assist with the fight against the pandemic.
New Jersey currently has 22,255 coronavirus cases and 355 deaths, according to CNN's tally.