NEW YORK (AP) — New York City nurses on strike restarted contract talks Friday with another one of the major hospital systems affected by the walkout that’s now in its fifth day.

The New York State Nurses Association said its bargaining team resumed meetings with their counterparts at the three impacted Mount Sinai hospitals at the request of a mediator.

Brendan Carr, CEO of the Manhattan-based health care provider, said Friday that administrators are working to bring the medical facilities to full capacity as they work toward a deal to end the city’s biggest strike of its kind in decades.

Mount Sinai has extended its contracts to retain thousands of temporary nurses to fill shifts and is also bringing on more specialized staffers to help bring surgical volumes back to normal, he said.

Nurses met Thursday night with NewYork-Presbyterian officials and a federal mediator in the first negotiations since roughly 15,000 nurses walked off the job Monday.

The hourslong meeting ran past midnight and ended with very little progress made, according to the union.

The hospital said in a statement that the discussions focused on addressing the union’s concerns about staffing levels, but that it still views the union’s proposals as “unreasonable.”

The union said it put forward revised proposals that hospital officials rejected without offering a counter proposal.

Both sides said there’s so far no further plans to meet.

“While we continue to be far apart, we are committed to bargaining in good faith,” NewYork-Presbyterian said in a statement. “We are committed to safe staffing and have the best staffing ratios in the city.”

Meanwhile union negotiations still have not resumed with Montefiore, the third major hospital system impacted.

The union said previously that it had expected to sit down with officials from the Bronx-based health care provider Friday, but the hospital disputed that claim, saying a meeting was never planned.

“NYSNA nurses respect the mediators and are ready and willing to come to the bargaining table when they call,” Nancy Hagans, the nurses’ union president, said in a statement. “We urge hospital executives to do the same.”

Each medical center is negotiating with the union independently, and not every hospital run by the three health care systems is affected by the strike.

The affected hospitals say their operations have been running smoothly since they hired thousands of temporary nurses to keep emergency rooms and other facilities open during the strike.

Dr. Philip Ozuah, president of Montefiore Einstein in the Bronx, one of the hospital campuses impacted by the strike, praised those still on the job.