The six member states of the Shanghai Cooperation Organization (SCO) yesterday pledged long-term friendship and cooperation while reiterating the commitment to a nuclear-weapon-free Central Asia at their seventh summit in the Kyrgyz capital.

"All leaders agreed to strengthen regional economic cooperation and implement multilateral projects, especially in energy, transport and telecommunications," President Hu Jintao told a joint press conference attended by the leaders of the SCO member countries.

They met the media after signing the Treaty on Long-term Neighborliness, Friendship and Cooperation, the Bishkek Declaration and an action plan for ensuring international information security.

According to the declaration, the leaders agreed that the treaty on a nuclear-weapon-free zone in Central Asia, which was signed in September last year, is of great importance to maintain nuclear non-proliferation and promote the peaceful use of nuclear energy.

They also expressed concern about drug trafficking from Afghanistan to the rest of Central Asia, and called for the establishment of an anti-drug buffer zone around the country and closer cooperation within the SCO framework. Afghanistan is an observer at the SCO.

Hu said that the treaty on long-term good-neighborliness, friendship and cooperation will raise mutual trust and cooperation among the member states to a higher level and inject new impetus into SCO development.

"China has previously signed similar bilateral treaties with the other five SCO member states, but the multilateral one will further strengthen understanding and trust between China and the other states," Chen Yurong, an expert at the China Institute of International Studies, told China Daily.

"The multilateral treaty will have a more binding force and lay a legal foundation for good-neighborly ties among the member states," Chen said.

At the one-day summit, the leaders also discussed SCO achievements since the last summit in Shanghai and drafted a blueprint for future collaboration on security, economy and foreign affairs.

Trade volume between China and Russia hit a record $33.4 billion last year while the figure with the other four SCO member states - Tajikistan, Uzbekistan, Kazakhstan and Kyrgyzstan - crossed $10 billion.

Later yesterday, Hu and the other SCO leaders arrived in Chelyabinsk of Russia, where they will observe the ongoing joint military exercise aimed at enhancing coordination in the fight against terrorism, separatism and extremism.

Established in 2001 in Shanghai, the SCO initially focused on fighting the three "evil forces" and other threats in the region, but has since expanded into a comprehensive organization which also includes cooperation in culture, trade and disaster relief.

"The focus of energy cooperation is how to maximize the interests of all the parties," Chen said. "The market and political trust are there."

China is undertaking more than 130 large-scale joint projects within the framework of the SCO, which will create a favorable environment for expanding business collaboration among member states, Chen said.

The leaders of the six member states have reiterated that the SCO does not target any country or organization and is part of international efforts to fight terrorism.