WASHINGTON - President Barack Obama told John Key that New Zealand had "well and truly earned our place at the table" of the nuclear security summit the United States President is hosting in Washington.

The leaders have broken after their first session, a working dinner at which Mr Key sat beside the Prime Minister of the Czech Republic, Jan Fischer, and the Prime Minister of Pakistan, Yusuf Raza Gilani.

Mr Obama greeted and chatted with each leader individually before the dinner which was when Mr Obama made the comment, Mr Key told reporters.

"We can offer leadership. We have got to a position where President Obama would like to see the world - free of nuclear weapons. The fact that we don't have nuclear capability or nuclear industry doesn't mean we don't have a strong voice."

The leaders are expected to issue a communiqué tomorrow setting out some concrete steps to make the storage of fissile material more secure.

Asked whether the summit was ignoring some of the big problems such as the nuclear growth of India and Pakistan and China's nuclear programme, Mr Key said that all those countries were involved and that was a good step.

"If we start off by either accusing countries or trying to box them into a corner we wont make progress."

Asked if the United States was applying pressure on leaders to back Security Council sanctions against Iran for continuing its programme to highly enrich uranium, Mr Key said that Mr Obama had also said in his opening remarks to leaders that it would not be productive to single out nations.

The primary objective of the summit was to prevent nuclear weapons falling into the hands of terroriststs.

Before the summit, Mr Key had a private lunch at the New Zealand embassy with United State Agriculture Secretary Tom Vilsack.

They talked about the concerns of 30 Senators had about the impact the Trans Pacific Partnership free trade agreement agreement would have on the US dairy industry.

"He recognizes that those in individual Senators are open for negotiation if you like and we can make our points and we should make our points to them.

They shared the view that the global demand for agricultural products was going to rise.

"He also shares the view that the real issue here is not whether there are going to be enough places in the world to sell agricultural products but whether there can be enough production to satisfy the world's demand."