Labour leader Andrew Little says the decision by the United States to send a naval vessel to New Zealand should not be seen in terms of "winners and losers."

He also said it was in New Zealand's interests to have "deep" military co-operation with the United States.

Little made his comments in a speech tonight to the New Zealand Institute of International Affairs in Wellington in which he chose to accentuate bipartisan issues.

The Labour Government's anti-nuclear policy in 1984 led to the suspension of the New Zealand from the Anzus security alliance, after which the US refused to send warships to New Zealand - until now.

Many anti-nuclear activists have displayed a sense of triumphalism in the decision.

They have hailed the US announcement by Vice President Joe Biden last week to resume ship visits as a victory for New Zealand's anti-nuclear movement and the US caving in.

Little said he was "especially pleased" with the announcement to send a US ship to New Zealand.

"I want to congratulate everyone on both sides of the Pacific who was involved in putting together this visit, which will do good on all sides."

But he said it was entirely wrong to look at the visit in terms of "winners and losers."

"International co-operation, including military co-operation, is very often about finding ways to enhance everybody's position, not about a zero-sum game of 'something for you means something less for me.'"

Little paid tribute to former National Prime Minister Jim Bolger, former National Foreign Minister Sir Don McKinnon and former Foreign Minister and New Zealand First leader Winston Peters for their role in maintaining good relationships with the United States.

He said the next Labour Government planned to "redouble our efforts" towards international agreements that further reduce nuclear stockpiles.

Little said Labour had discussed the Five Eyes intelligence sharing relationship with Biden in its meeting with him last week.

Such intelligence sharing was "vital in confronting ongoing security challenges, including from barbaric groups like Al Qaeda and Isis."

"It is also strongly in New Zealand's interests that we have deep, friendly military co-operation with the the US," Little said.

Little touched on the Trans Pacific Partnership free trade agreement his party opposes  that is waiting to be ratified by its 12 participating countries.

But in response to a question, he repeated his promise not to withdraw from the TPP if Labour formed the next Government, if the TPP had already been ratified.

If he had not been ratified "Labour would welcome the chance to be part of resumed negotiations leading to an agreement that does away with more tariffs, without curtailing the ability of countries to make laws in their own interests."

He also restated that Labour would legislate to ban house sales to offshore-asked foreigners, even though there was no provision preserving New Zealand's right to do so in the TPP.

Other countries, including Australia, had such rights to do so.

Asked by a member of the audience about British Labour, Little said the party needed a unifying leader "and it's pretty clear to me that Jeremy Corbyn isn't that.