North Korea has signed a non-aggression treaty with the Association of the South East Asian Nations (Asean), in a largely symbolic move.
Pak Ui Chun, North Korea's foreign minister, signed the Treaty of Amity (Tac) and Co-operation with the Asean at a ceremony on Thursday, the last day of the annual security conference.
George Yeo, Singapore's foreign minister, said Pyongyang's signing of the treaty was "quite an unexpected development", while South Korea welcomed the development.
The move has no direct impact on the six-nation efforts to strip Pyongyang of its ability to produce nuclear weapons.
However, it is a rare sign of reaching out to the international community by North Korea.
The Tac, which came into force in 1976, requires signatories to renounce the use or threat of force and calls for the peaceful settlement of conflicts.
Aside from the 10 Asean members, 11 other countries outside the regional bloc have signed the treaty.
The signing comes amid moves by North Korea to dismantle its nuclear program in exchange for economic and political incentives, including normalisation of ties with Japan and the United States.