Nurses have issued their first strike notice after not agreeing with the outcome of salary negotiations.

But a District Health Board spokeswoman says emergency medical services will be available when nurses strike for 24 hours next month.

The strike notice has been issued for the day of July 5, from 7am.

DHB spokeswoman Helen Mason says people needing urgent medical attention should still go to hospital when nurses strike in July.

Helen says DHBs would implementing "contingency plans to ensure the safety of patients and staff".

The strike should not deter or delay people needing medical attention from going to hospital that day, she says.

The New Zealand Nurses Organisation notified DHB chief executives that they would strike on Wednesday.

Next week they will decide whether to strike for a second day on July 12.

The call to strike came after NZNO members voted to reject the DHB's revised pay increase offer of 9 per cent for all member nurses by August 2019.

The Multi Employer Collective Agreement (MECA) offer included a $2000 lump sum payment to DHB nurses covered by the NZNO, and doubling their on-call hourly allowance from $4 to $8, and $6 to $10 on public holidays.

It offered a $38 million investment to hire another 600 nurses and midwives, increasing staffing levels 2 per cent.

- Stuff