More nurses will be placed in NSW hospital wards under a new agreement affirming the government's pre-election commitment to "safe staffing levels".

Under the agreement, ratios of at least one nurse to three patients would be introduced for emergency departments and maternity wards, followed by similar requirements across much of the public hospital system.

The NSW government announced on Thursday it had signed a memorandum of understanding with the NSW Nurses and Midwives Association (NSWNMA) to introduce the changes.

Building on pre-election commitments by the government, a "good faith" process has been set out, including a time frame to enshrine Safe Staffing Levels in the public health nurses' and midwives' NSW award.

The government has committed to introducing ratios across EDs, ICUs and maternity wards within its first term.

The government previously committed to hiring an additional 1200 nurses within the same time frame.

The NSWNMA has repeatedly called for enshrined nurse-to-patient ratios which it says will reduce wait times and improve patient outcomes, as well as take pressure off staff.

NSWNMA general secretary Shaye Candish said the latest agreement was reassurance for nurses and midwives but was only the latest step in "much larger reform" the union and its members were fighting for.

"Implementation of the safe staffing policy can continue in earnest, and we intend to maintain pressure on the government to invest further in the workforce until all specialty areas have safe staffing ratios across the system," Ms Candish said.

Premier Chris Minns said nurse-to-patient ratios would mean the world to burnt-out health workers.

"We made a promise to the people of NSW to implement safe staffing levels in NSW public hospitals, and that's exactly what we're delivering," Mr Minns said.

Minister Ryan Park said the state's 58,000 nurses and midwives were the backbone of the health system.

"Safe staffing levels will support better health outcomes for patients while also attracting and retaining more skilled nurses and midwives in the NSW health system," he said.

NSW Treasurer Daniel Mookhey said more could be spent on frontline health workers by managing the state's finances responsibly, including a $7 billion deficit.

"The Minns Labor government is making the prudent and necessary decisions to fix the fiscal mess left by the former government and ensure we can fund the essential services people rely on," he said.