Chinese Vice Premier Zhang Gaoli on Tuesday proposed more informal meetings between Chinese leaders and those of the Association of Southeast Asian Nations (ASEAN), and that the two sides sign a "cooperation treaty."

These mechanisms will allow China and the ASEAN to deepen political mutual trust, Zhang said while addressing the 11th China-ASEAN Expo, which opened on Tuesday in Nanning of south China's Guangxi Zhuang Autonomous Region.

He said China wants to be the first among ASEAN dialogue partners "to conclude a treaty on good-neighborliness, friendship and cooperation with ASEAN countries," as a legal and institutional guarantee for their long-term friendship.

Zhang said the leaders meetings would be informal and would be held in China on an irregular basis in conjunction with the China-ASEAN Expo and the Boao Forum for Asia.