The leaders of 54 countries have entered round table talks about nuclear security at the Nuclear Security Summit in Seoul today.
Prime Minister John Key is among those at the summit, which was instigated by US President Barack Obama and first held in 2010.
After a working dinner last night, the leaders entered the main summit session today. Mr Key was seated between Japan's Prime Minister Yoshihiko Noda and Canada's Prime Minister Stephen Harper. Japan is among the countries most strongly opposed to North Korea's nuclear programme and has criticised strongly North Korea's proposals for what it claims is a peaceful rocket launch planned for next month.
US President Barack Obama was among the last leaders to arrive in the conference hall and made a point of greeting most other leaders as he made his way to his seat next to Korean President Lee Myung-bak, who is chairing the Summit. Prime Minister John Key got a squeeze on the arm from Obama as he walked past Mr Key's chair - the pair had already spoken in the Leaders' lounge before entering the summit.
Obama stopped to talk to both Mr Noda and Mr Harper at length.
Mr Key will give his statement to the conference this afternoon and has said he would challenge countries with nuclear stockpiles to go further in securing and eliminating those materials.
Security is tight for the summit - x-ray machines and facial recognition technology scan all delegates, workers and media into the conference centre and sniffer dogs and lines of police and security are stationed outside. The checks have been so extensive even the toilet cisterns have discreet security tape on them so that tampering can be detected.
Mr Key said the summit also provided a good opportunity to meet on the sidelines with leaders he would not normally get to see, as well as bend the ear of the powerful countries - including pushing for progress on trade talks with both India and South Korea.
It was also a chance to try to shore up support for New Zealand's bid for a seat on the Security Council in 2015. Turkey is now also contesting the seat as well as Spain, which has taken some support from New Zealand. Mr Key said the summit would provide the chance to lobby leaders of countries which had not already committed a vote.
There are five permanent members on the Council - the United Kingdom, France, China, Russia and the United States - as well as 10 temporary members elected by member nations. New Zealand will contest one of the two Western Europe and Others Group seats.
He held bilateral talks with Vietnam Prime Minister Nguyen Tan Dung this morning, during which they were expected to discuss progress in the Trans Pacific Partnership talks. He will meet with Thailand's first female Prime Minister Yingluck Sinawatra, Chile President Sebastien Pinera and Mr Harper later today before leaving to return back to New Zealand.
The leaders are expected to issue a communique from the meeting later today - much of which was written in advance by the 'sherpas' - the name given to Summit officials. It is expected to call for further reductions in nuclear materials - the goal of the summit is to secure all nuclear and radioactive materials by 2014.