John Key. Pic: NZPA

Wellington, April 16 NZPA - New Zealand was invited to United States President Barack Obama's nuclear proliferation summit because of its anti-nuclear record, a high ranking official has confirmed.

Mr Key earlier in the week attended the summit with more than 40 other leaders in Washington -- the largest assembly hosted by a US leader since the founding conference of the United Nations in 1945.

New Zealand had a falling out with the US in the 1980s over the nuclear-free debate and resulting controversial legislation which led to New Zealand's exclusion from the Anzus military alliance with Australia and the US.

In recent years countries have set the issue aside.

Assistant Secretary of State Kurt Campbell told the Dominion Post that the summit "would not have been complete" without New Zealand.

"The truth is, in many respects, it is recognition of the ideals and policies that New Zealand has espoused for decades."

Dr Campbell said there were some areas of difference but the two countries were in discussions about areas they could work more closely together including "appropriately conceived and implemented" exercises and training relevant to join areas of common pursuit,

This week Mr Key told NZPA he had decided not to go into New Zealand's record in the area during the summit talks.

"While everyone understands New Zealand's history in this field, I think it's important, I can allude to it, but I don't think the argument at this point is to argue everybody should follow the same pathway that New Zealand has, but to point out that I think that a world free of nuclear weapons is a world that we should all want to see and that the threat of nuclear weapons falling into the wrong hands, whether that be a rogue state or a rogue organisation like al Qaeda is a very real threat and it poses potentially catastrophic outcomes for all of us."

Labour leader Phil Goff yesterday said Mr Key had not shown any leadership on the issue and should have endorsed United Nations Secretary General Ban Ki Moon's proposal for a convention to eliminate nuclear weapons among other measures.