"Everybody agrees in all of the countries in the region, except the North Koreans, that it's unacceptable for North Korea to have nuclear weapons," Gary Samore, from the International Institute for Strategic Studies (IISS), said at the end of the Asian Security Conference.

US Deputy Defence Secretary Paul Wolfowitz attended the conference on Saturday with his main message a call for a united regional stance to pressure Pyongyang.

Australian Defence Minister Robert Hill delivered a message to Pyongyang that the United States and its allies were now fully focused on forcing it to dismantle its nuclear program following the US-led war that ended Saddam Hussein's rule in Iraq.

"On the weapons of mass destruction front, the emphasis clearly has now switched from Iraq to North Korea," Hill told reporters after the end of the conference, which the IISS organised.

However although there was consensus on the final goal of trying to keep the Korean peninsula nuclear free, there was little agreement on how this would be achieved.

Some at the conference were disappointed that the United States was intent on brokering a common stance with China, South Korea, Russia and Japan without a bigger role for the United Nations.

"Given the global nature of the challenge, there was little objection from the participants when an Australian analyst indicated that the United Nations Security Council would have to be brought into the picture," IISS chairman Professor Francois Heisbourg said.

"However I'm afraid... the damage done during the Iraq crisis makes it more difficult to travel down the United Nations Security Council route."

Samore, the IISS's director of studies, said there was little indication South Korea and China supported tentative US proposals to impose economic sanctions against North Korea.

"China and South Korea are in particular very concerned that a policy of sanctions would be very dangerous," Samore said.

"It could either cause North Korea to react in a very negative way, perhaps even in a violent way.

"Or it could cause North Korea to collapse, which from Seoul and Beijing's standpoint would be very destabilising for them."

Although North Korea overshadowed the conference, which was the first major security meeting attended by international defence ministers since the Iraq war, terrorism, India-Pakistan relations and US military bases in the Asia Pacific were also high on the agenda.