NANNING - The eighth China-ASEAN Expo kicked off in the southwestern city of Nanning in Guangxi Zhuang autonomous region on Friday, with economic cooperation and environment protection on top of the agenda.

Premier Wen Jiabao announced the opening of the expo at a ceremony, which was attended by leaders from both China and the Association of Southeast Asian Nations (ASEAN) member countries.

About 2,300 enterprises will participate in the expo, which runs till Oct 26.

Vice Minister of Commerce Gao Hucheng said at the ceremony that the expo will fully display the remarkable achievements in Sino-ASEAN cooperation in the past 20 years and bring broad business opportunities and rosy prospects of the China-ASEAN Free Trade Areas (CAFTA).

Gao said since the establishment of China-ASEAN relations 20 years ago, China and ASEAN have advanced friendly and mutually beneficial cooperation in a wide range of areas, especially in the economic and trade arenas.

In his speech at the opening ceremony, Malaysian Prime Minister Najib Tun Razak said China and ASEAN should be mindful of the economic challenges Europe and the US are facing and their impact on Asia.

Malaysia is the country of honor at this year's expo.

The region needs to look for alternative sources to support growth as exports to Europe and the US are affected, Najib said.

Environmental protection and sustainable development are critical issues that will be addressed at the expo, said Najib, who urged for more efforts in developing clean energy and reducing fossil fuel emissions.

ASEAN is made up of Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, the Philippines, Singapore, Thailand and Vietnam.