ST.PETERSBURG - The leaders of Russia, China and four Central Asian nations met in Russia's former imperial capital Friday at a summit intended to bolster the status of their security group and tighten their cooperation against terrorism.

Russian President Vladimir Putin is also using the summit to reassure China that his efforts to build closer ties with the West do not threaten Russia's burgeoning ties with Beijing.

Putin, Chinese President Jiang Zemin and leaders of former Soviet republics Kazakhstan, Kyrgyzstan, Tajikistan and Uzbekistan held their first meeting at a czarist palace in Peterhof outside St. Petersburg and were to move to the Marble Palace in the city itself later in the day.

They were due to sign the charter of the Shanghai Cooperation Organization - a document that would give the group a formal international legal status. The six leaders were also expected to form a joint body to coordinate their efforts to combat terrorism in the region.

"We have worked energetically and productively to harmonize our positions and prepare our charter," Putin said as he and the other leaders sat down for talks in the gilded Grand Palace in Peterhof.

The group, which was set up in Shanghai in 1996, initially included five nations and called itself the Shanghai Five. Last year it embraced Uzbekistan and renamed itself to reflect more ambitious goals.

The original group was created to help defuse tensions along China's 7,500-kilometer (4,600-mile) border with the other member nations. Recently, it has focused increasingly on combined efforts to fight extremism, terrorism and separatism.

Russia and China, which have dominated the group, describe it as an important tool to increase stability in Asia and foster the concept of a "multipolar world" intended to offset perceived U.S. global domination.

The shared domination of Russia and China over strategically placed, resource-rich Central Asia ended after Sept. 11, when Putin gave a quick blessing for the U.S. military deployment there for operations in Afghanistan.

The U.S. push into the region has troubled China, which expressed support for the U.S.-led war on terrorism but remains nervous about the American military presence near its borders.

Putin sought to assuage China's concern about the U.S. military presence in the region, saying in an interview this week that the U.S. military presence in Central Asia was key to defeating Islamic terrorists who threaten to destabilize the entire region. He said that Russia no longer considers the United States a rival, but a partner in its relations with other ex-Soviet republics.

Uzbekistan has treated the Shanghai group with increasing neglect since its relations with the United States improved dramatically thanks to its offer to host U.S. troops last fall. Some analysts say Uzbek President Islam Karimov is increasingly looking to the United States as Uzbekistan's chief protector and trying to distance his nation from Moscow and Beijing.

Putin also sought to soothe Beijing's uneasiness about increasingly warm ties between Russia and the West, which helped him reach a nuclear arms deal with the United States and a cooperation agreement with NATO in recent weeks.

On the eve of the summit, Putin, a St. Petersburg native, met separately with Jiang at the city's Yusupov Palace - the place where Grigory Rasputin, the notorious favorite of Russia's imperial family, was murdered by his enemies in 1917.