A nurses union says having more staff will reduce violence in emergency departments.

There have been more than 7,000 assaults of public health employees in the two years to April.

The Australasian College for Emergency Medicine is calling for around-the-clock security guards in all EDs.

NZNO's Kerri Nuku says reducing wait times will lower the tension.

"If we had more nurses, more doctors on the floor to be able to deal with the crisis- ED departments across the whole workforce are short."

LISTEN ABOVE