The leaders of the Shanghai Cooperation Organization on Wednesday ended their regional summit in the Kazakh capital, Astana, by criticizing U.S. plans for a missile shield, saying it could damage strategic stability and global security.

The regional security and economic bloc, grouping Russia, China, Kazakhstan, Kyrgyzstan, Tajikistan and Uzbekistan, adopted a declaration condemning any unilateral build-up of missiles defense.

The declaration did not mention any nation specifically. The United States has said its proposed European missile defense shield is meant to protect the region from potential attack by Iranian missiles. But Russia fears the system will weaken its nuclear deterrent.

Earlier in the day, Iranian President Mahmoud Ahmadinejad urged Central Asian nations to create a new world order that ends the domination of what he called the “enslavers and colonizers of the past” — a reference to Western powers.

Addressing the summit as an observer, he said all of the participating nations have a history of avoiding conflicts and together can bring peace to the world. He blamed unnamed Western countries for global instability.

After the summit, the leaders of China and Russia, Hu Jintao and Dmitry Medvedev, urged Mr. Ahmadinejad to take a “more constructive approach” in resolving a dispute with six world powers about Tehran's nuclear program.

Six major powers, Russia, China, the United States, Britain, France and Germany, have been trying to persuade Iran to stop sensitive nuclear work in return for diplomatic incentives, but the talks have been stalled for months.

In private talks ahead of the summit Tuesday, Chinese President Hu Jintao also urged Mr. Ahmadinejad to resume the six-nation talks, saying Iranian steps to establish trust and promote dialogue would be in the interest not only of Iran but of the Middle East as a whole.

Western powers accuse Iran of trying to develop nuclear weapons under the cover of a civilian energy program. Lavrov said Mr. Ahmadinejad told his Russian counterpart that Iran has no intention of becoming nuclear-armed.

The leaders were also expected to discuss expanding the six-member group for the first time since it was founded 10 years ago. India, Pakistan and Iran who have an observer status are seeking full membership in the group, while Mongolia said it is not seeking to change its observer status.