The veiled warning came at a meeting of the Shanghai Cooperation Organization and on the eve of major war games between Russia and China.
The SCO was created 11 years ago to address religious extremism and border security in Central Asia, but in recent years, with countries such as Iran signing on as observers, it has grown into a bloc aimed at defying U.S. interests in the region.
"Stability and security in Central Asia are best ensured primarily through efforts taken by the nations of the region on the basis of the existing regional associations," the leaders said in a statement at the end of the organization's summit in the Kyrgyz capital, Bishkek.
Iranian President Mahmoud Ahmadinejad, attending the summit for the second consecutive year, criticized U.S. plans to put parts of a missile defense system in Eastern Europe as a threat to the entire region.
"These intentions go beyond just one country. They are of concern for much of the continent, Asia and SCO members," he said.
Washington has claimed the system would help protect against potential Iranian missiles.
Russian President Vladimir Putin didn't mention the United States in his speech, but he said that "any attempts to solve global and regional problems unilaterally are hopeless."
He also called for "strengthening a multi-polar international system that would ensure equal security and opportunities for all countries" — comments echoing Russia's frequent complaints that the United States dominates world affairs.
Moscow has also bristled at Washington's plans to deploy the anti-missile system in Poland and the Czech Republic, saying the system would threaten Russian security.
Moscow and Beijing have developed what they dubbed a "strategic partnership" after the Soviet collapse, cemented by their perceptions that the United States dominates global affairs.
In 2005, the SCO called for a timetable to be set for the withdrawal of U.S. troops from two member countries, Uzbekistan and Kyrgyzstan. Uzbekistan evicted American forces later that year, but Kyrgyzstan still hosts a U.S. base, which supports operations in nearby Afghanistan.
Russia also maintains a military base in Kyrgyzstan.
The SCO, whose members are some of the world's biggest energy producers and consumers, also discussed ways to enhance energy cooperation. Washington has supported plans for new pipelines that would carry the region's oil and gas to the West and bypass Russia, while Moscow has pushed strongly to control the export flows.
A further sign of the group's intention to influence energy markets was the participation in the Bishkek summit of Turkmen President Gurbanguli Berdymukhamedov, whose country is the second-largest producer of natural gas in the former Soviet Union after Russia. Turkmenistan is not an SCO member; the president was attending as a guest.
Chinese, Russian, Central Asian leaders show off military might
The presidents of Russia, China and four other Central Asian states attended unprecedented joint military exercises on Friday, intended as a display of strength before the Western world.
The vast show of firepower at a training ground in the Russian province of Chelyabinsk near the Kazakh border was the culmination of a nine-day exercise dubbed ""Peace Mission 2007"" that began in northwest China, AFP reported.
It involved some 6,000 personnel from the six countries of the Shanghai Cooperation Organisation (SCO): China, Kazakhstan, Kyrgyzstan, Russia, Tajikistan and Uzbekistan.
A lone bugle player formally opened the exercises, and over a two-hour period helicopters, fighter jets and tanks went in hot pursuit of some 1,000 heavily-armed "terrorists" who had taken over a village fabricated for the exercises -- soundly crushing them.
While Russia footed most of the bill for its phase of the exercises, spending some 80 million dollars (60 million euros), they marked a new level of military cooperation with China after the two countries held their first-ever joint maneuvers two years ago.
Beijing contributed 1,700 personnel and sent warplanes and helicopters to the Chebarkul training ground in the rolling Urals countryside.
After "scrupulous" preparation, the six countries had "resolved all questions of cooperation," Russian deputy defense minister Alexander Balousov said.
The SCO grew out of a regional effort in the mid-1990s to reduce military forces along common borders, and has evolved into active military and economic cooperation, with the focus on Central Asia
