Key Points:

New National leader John Key continued to stamp his authority on the party yesterday, announcing his unswerving support for New Zealand's anti-nuclear legislation.

Mr Key's endorsement of a law which has kept nuclear-powered and -armed warships out of New Zealand harbours was intended to exorcise former leader Don Brash's infamous "gone by lunchtime" comment about the future of the law under a National government.

Mr Key also poured cold water on some National supporters' desire for New Zealand to revive the Anzus defence alliance with Australia and the United States, saying the pact had "essentially been dead for 20 years now".

There was scope for a constructive relationship between New Zealand and the United States beyond Anzus, Mr Key said.

"I think it would be fair to say that I have a very much more positive view of the United States and its role in world affairs than most ministers in the Clark Government."

During last year's election campaign, Labour attacked National's inconsistencies on defence and nuclear ship visits, and Mr Key will hope his strong language yesterday can defuse them as issues.

"National's position has been in limbo in relation to nuclear ships, so I want to make it perfectly clear that I support the nuclear-free legislation," Mr Key said.

"For as long as I am leader of the National Party, the nuclear-free legislation will remain intact."

Mr Key also rejected a compromise proposal made during the election campaign for a National-led government to hold a referendum on the nuclear legislation.

"I think New Zealanders have a long-held view that this is important to our nation-building. I think they see it as New Zealand standing up strongly for something it believes in.

"I believe in that position and I see absolutely no reason to change it."

Mr Key said he wanted to work with Prime Minister Helen Clark to foster New Zealand's interests, and to maintain consistency between the two parties on foreign affairs.

"As a general rule, it's in the best interests of New Zealanders that both major political parties approach it on a bipartisan basis," Mr Key said.

"When we ask our New Zealand troops to go into combat overseas, they deserve to do that on the basis of not second-guessing what the Opposition of the day is doing."

Yesterday, National MPs held a seminar to discuss foreign affairs and defence, and Mr Key's speech to open the session was the former finance spokesman's first venture into commenting on world affairs.

He proposed more public consultation on defence goals and strategies and a closer defence relationship with Australia, and stressed the need to build on relationships with South Pacific nations.

The speech followed Tuesday's personal values speech and Wednesday's speech on environmental issues, and continued Mr Key's attempt to increase voters' understanding of him and his policies.

"I think it's very important as the new leader to make clear some positions on things where the media have said that they don't know where I stand," he said.

"I think that in the past three or four days you probably have gained a much clearer view of where I stand.

"Foreign affairs and defence are very important to us and I think it's very important that you understand where I'm coming from, and I don't want any ambiguity."

Defence Minister Phil Goff dismissed Mr Key's nuclear-free stance as opportunism.

"National does not have a conviction for a nuclear-free New Zealand," Mr Goff said.

"They have a political antenna that each time they have raised the suggestion they might abandon it, they've been told loudly and clearly that New Zealanders want New Zealand to be nuclear-free.

"As long as their policy is driven by political expediency, rather than by conviction, you could never really rely on them holding to that policy if and when they achieved power."