The United States Navy is sending the USS Sampson to New Zealand, the first US warship to visit New Zealand in 33 years.

Prime Minister John Key said he had granted approval for the ship to visit to take part in the International Naval Review for the New Zealand Navy's 75th birthday celebrations next month.

Under New Zealand's anti-nuclear law, the Prime Minister has to be satisfied that any visiting ship is not nuclear armed or powered.

"I have granted this approval after careful consideration of the advice provided by the Ministry of Foreign Affairs and Trade," he said.


The law has never required foreign countries to confirm or deny whether their vessels are nuclear armed or powered.

But the US chose not to send any ship as part of the reprisals for the anti-nuclear policy, which effectively suspended New Zealand from the Anzus security alliance in 1985.

"The process for considering the visit by the USS Sampson is the same as that used for all ships attending the International Naval Review. This process has been used for all military ships visiting New Zealand since the legislation was enacted.

"New Zealand looks forward to the USS Sampson's participation in the International Naval Review to mark the Royal New Zealand Navy's 75th anniversary. The visit is a further reflection of the depth of the bilateral relationship with the United States," Key said.

The USS Sampson is an Arleigh-Burke class destroyer and is 155m long.