Patel has spent recent days in the capital Wellington meeting with senior government ministers as well as intelligence bosses and law enforcement officials.

"Some of the most important global issues of our times are the ones that New Zealand and America work on together," Patel said in a video released by the US Embassy in Wellington.

Patel singled out "countering the CCP" as a priority, referring to the Chinese Communist Party.

New Zealand is a member of the "Five Eyes" intelligence-sharing alliance alongside the United States, Britain, Canada, and Australia.

"The FBI cannot do it alone," Patel said.

"Our partners in the Five Eyes are our greatest partners around the world. But we need all of them... to get after the fight and put the mission first."

The US Embassy in Wellington said the FBI office would investigate "terrorism, cyber crime and fraud, organised crime and money laundering, child exploitation, and foreign intelligence threats".

It will also cover FBI partnerships in Antarctica, Samoa, Niue, the Cook Islands, and Tonga.

The minister responsible for New Zealand's spy agencies, Judith Collins, said the FBI was a valued intelligence partner.

The FBI has hundreds of special agents spread across the world.