Secretary of State for the Pacific The United States Coast Guard is set to extend its surveillance of the Pacific in close concert with New Zealand in a bid by both countries to curb illegal fishing.

But the issue of a ship visit by the Coast Guard to a New Zealand port is not yet on the agenda.

Washington's Assistant Secretary of State for the region, Kurt Campbell, demurred on the question yesterday on the edges of the US-NZ Partnership Forum in Christchurch.

"I think there are some specifics that will be worked out over time between the appropriate defence and Coast Guard officials on both sides," he told the Herald.

Foreign Minister Murray McCully, in speech notes to the closed-door conference, said it was time to step up collective surveillance activity with the US and Australia "to provide a comprehensive assault on illegal activity within our region".

About $2 billion worth of fish a year was taken legally from the zones of the 14 states of the Pacific Islands Forum, and $400 million worth was taken illegally.

NZ is the largest provider of aerial surveillance of Pacific Island exclusive economic zones and, Mr McCully said, "the US Coast Guard is a stalwart and pragmatic partner in those efforts".

The US Secretary for Homeland Security, Janet Napolitano, who is responsible for the Coast Guard, was to have been Washington's key delegate to the conference but the killing of a customs agent in Mexico changed her plans.

Greater co-operation between the defence forces of the US and New Zealand has been occurring since 2007 under an agreement the Americans wanted kept secret and revealed only by the WikiLeaks diplomatic cables.

Asked about the restoration of the relationship by stealth, Dr Campbell did not want to speak for another Administration but said the Obama Administration had tried to be transparent.

He said it had tried "to make a very public and specific appeal to what we want to accomplish" in terms of the US-NZ relationship.

"While we don't comment generally on what is contained in the WikiLeaks releases, it has been deeply embarrassing and very challenging for American foreign policy interests," he said.

"The WikiLeaks has created enormous complications for us in a variety of our relationships."

Alluding to the anti-nuclear laws that keep the US from sending its navy to New Zealand, Dr Campbell said: "There is still sensitivity around certain issues. I think that sensitivity is understandable.

"But with care and a recognition of the limits on both sides I think there are any number of areas where the United States and New Zealand could work more comfortably and creatively together."