South Korea's top diplomat on Saturday called for sending a "united message" against North Korea's nuclear development program at a foreign ministerial gathering led by the Association of Southeast Asian Nations (ASEAN).

Foreign Minister Cho Tae-yul made the call during the ASEAN Plus Three foreign ministers' meeting in Vientiane, noting that North Korea is causing uncertainties on the Korean Peninsula and the region through its provocations and military cooperation with Russia.

"Member states need to send a stern and united message that North Korea's nuclear development will not be tolerated," Cho said during the ASEAN-led meeting that also involves South Korea, Japan and China.

Cho also said the three-way cooperation among Seoul, Tokyo and Beijing serves to promote cooperation among ASEAN Plus Three members, hailing the three countries' trilateral summit in Seoul in May, which marked the first such meeting in more than four years.

Meanwhile, Chinese Foreign Minister Wang Yi described ASEAN Plus Three as a channel to lead cooperation in Northeast Asia, noting opportunities for cooperation despite changes to the international situation and challenges to the future of Northeast Asia.

ASEAN Plus Three, which launched in 1997, consists of the 10 ASEAN members, as well as South Korea, Japan and China, and has served as a framework to promote regional cooperation. (Yonhap)