ASEAN remains hopeful it can still entice the five permanent members of the UN Security Council to sign a regional nuclear-weapon-free agreement after a scheduled signing was postponed on Sunday, a Cambodian foreign ministry spokesman has said.

Four of the “P5” countries – the UK, Russia, France and the US, with the other being China – have expressed reservations about signing a protocol within the Southeast Asia Nuclear Weapon-Free Zone (SEANWFZ) treaty, which was to take place during this week’s ASEAN meetings in the capital.

"Four members of P5 have expressed reservations,” Kao Kim Huorn, secretary of state at the Ministry of Foreign Affairs, said at the Peace Palace today. “Their reservations were quite different. In the case of France, for example, it has to do with self-defence . . . in the case of the [UK], the reservation was to do with . . . development."

Russia had expressed “broader” concerns relating to armed forces, allies, transit and to what extent the protocol was a pact, he said.

Under the treaty, the 10 ASEAN states must not develop, possess or manufacture nuclear weapons. If the UK, Russia, the US, France and China sign the protocol, they would agree not to contribute to any regional member violating the treaty.

Kao Kim Huorn said the four countries’ reservations meant the region now had to look to the next ASEAN Summit in Phnom Penh in November for the outcome it wanted.

“There were possibly three documents to be signed,” he said. “The [SEANWFZ] commission decided to not cancel but postpone until the members and ASEAN were able to work closely with [the five] to resolve the issues.”

“They believe these should all be signed together, back to back. We hope the work can still be completed by November. We are surprised by the last-minute reservations  . . . ASEAN has been working hard for the last 12 years to make this happen," he added.

In his speech to open the 45th ASEAN Foreign Ministers Meeting this morning, Prime Minister Hun Sen said one of the priorities of ASEAN is to maintain regional peace and security.

The SEANWFZ Treaty is one of the “instruments and mechanisms to ensure this could be achieved”, he said.

To contact the reporters on this story: Shane Worrell at [email protected]

Bridget Di Certo at [email protected]