NEW YORK (AP) — With a strike deadline looming, contract negotiations continued Sunday between three New York City hospitals and the union representing nearly 9,000 nurses prepared to walk out on Monday, union officials said.

Talks were under way with Mount Sinai Hospital in Manhattan and Montefiore Medical Center in the Bronx, which both have more than 1,000 beds, and Mount Sinai Morningside and West, New York State Nurses Association President Nancy Hagans said on a conference call with reporters. Negotiators have reached tentative agreements at several other city hospitals.

“We have said always our number one issue is the crisis of staffing, chronic understaffing that harms patient care,” Hagans said.

She said negotiations were resuming for the first time since Thursday with Mount Sinai management. Talks with the other hospitals have been ongoing.

The hospitals have taken steps to prepare for a strike through patient transfers, directing ambulances elsewhere and postponing elective surgeries.

In a statement, Mount Sinai said the union’s focus on staffing-to-patient ratios “ignores the progress we have made to attract and hire more new nurses, despite a global shortage of healthcare workers that is impacting hospitals across the country.”