Negotiations between the nurses’ union and three major hospital systems are set to resume Friday morning at the Javits Center, after talks again ended Thursday night with no significant breakthrough.

About 15,000 striking nurses will return to picket lines for a 12th day in what has become a historic labor stoppage, as thousands remain without contracts and uncertain about next steps.

Union officials said negotiations on Thursday began several hours later than scheduled. NewYork-Presbyterian disputed that account, releasing a statement late Thursday insisting its bargaining team had been present since 10 a.m. and had spent the morning working with a mediator before meeting with the union’s bargaining committee later in the day.

Meanwhile, some nurses face the prospect of losing health coverage if the strike continues. Montefiore Medical Center has warned union members they have until February 1 before being required to begin paying for their own health benefits. The hospital says it is obligated under federal law to provide advance notice of the deadline, noting that it currently offers free healthcare coverage to nurses.

Thursday night, unionized nurses met again with hospital executives in an effort to reach contracts addressing wages, staffing levels, and patient safety concerns.

“It’s the tactics management keeps playing,” said Doris Anning, a labor and delivery nurse at Montefiore. “Management has been in and out of the room with no agreement on anything.”

Many nurses are now struggling financially after missing their first paychecks this week, adding further pressure to reach a resolution.