The Green Party says it is "concerned" about Rocket Lab launching a rocket for a US intelligence agency off the coast of New Zealand.

Rocket Lab announced yesterday it would be launching a small satellite for the US National Reconnaissance Office, a US agency which provides satellite imagery for military and intelligence use.

The launch will take place at Rocket Lab's Mahia launch site near Napier.

SUPPLIED The payload in question is launched as part of a "Birds of a Feather" programme.

All New Zealand-based rocket launches by the company require sign off from Economic Development Minister Phil Twyford.

Green Party foreign policy spokeswoman Golriz Ghahraman said her party was "concerned" about the launch given the current US administration's aggressive moves in the Middle East.

SUPPLIED Golriz Gharaman said the party was concerned about the launch.

"The Green Party has a longstanding opposition to mass surveillance conducted in international contexts that fall outside of the rule of law," Ghahraman said.

"We are concerned in this instance, that surveillance and information sharing comes in the context of the American president expressing an intention to launch attacks against Iran, including cultural and civilian targets that would constitute war crimes."

"New Zealand should instead do all it can to de-escalate conflict by all parties."

The Green Party are part of the Government through a confidence and supply arrangement.

Ghahraman said the decision had been made by Twyford himself as minister and the Green Party weren't involved in individual decisions on rockets.

"We believe there needs to be independent principled foreign policy in assessing our national interest, including taking account of concerns that intelligence sharing, even with our allies, may be used to further international conflict, which is not in the interest of global peace."

Twyford told Stuff the Greens had signed off on the wider principles the Government used to decide on individual payloads.

"I am satisfied they have been adhered to in this instance," Twyford said.

Head of New Zealand space agency Peter Crabtree said in order to gain approval each payload had to meet a series of tests - including "our national security and wider national interest."

Payloads with "the intended end use of supporting or enabling specific defence, security or intelligence operations that are contrary to government policy" would not be allowed Crabtree said.

"New Zealand has a deep and long-standing security relationship with the US Government and a history of collaboration across a range of issues."

Crabtree said the specific launch contained a classified payload but said data from the National Reconnaissance Office was used "to inform decision making by national policy makers and military and civil users in the US and in US partner nations, including New Zealand."

While Rocket Lab launches rockets in New Zealand and is headed up by Kiwi Peter Beck, it is in fact an American company with a New Zealand subsidiary.

The Spinoff reported last year that the New Zealand Space Agency had pushed then-minister Simon Bridges in 2017 not to include the phrase "non-military" in legislation enabling launches, as this would rule out a "potentially valuable client base."

Crabtree told The Spinoff that New Zealand was "wholly committed to the safe, secure and peaceful use of space" and that technology developed by the military "can make a major difference to the lives of millions of people."

Rocket Lab declined to comment.