The U.S. government today added three Chechen rebel groups to its blacklist of terrorist organizations, saying their leaders were linked to al Qaeda and were involved in the seizure of more than 800 hostages at a Moscow theater last October.

The decision gave a boost to the Kremlin's claim that Russia is fighting more than just a separatist movement in its restive southern republic. It comes as the Bush administration lobbies intensely for Russia's acquiescence to a new U.N. Security Council resolution that would smooth the way toward military action against Iraq.

The State Department spokesman, Richard Boucher, on Thursday denied that the timing of today's announcement was aimed at securing Russian support at the United Nations, saying the United States had been evaluating the Chechen groups for months.

Their identification as terrorist organizations gives the U.S. government the right to seize any financial assets they hold in the United States, but there is no indication the groups have any.

Russian officials have applauded the designation, saying it shows that Washington has finally recognized the true nature of the conflict that has raged in the republic for the better part of a decade, with a three-year reprieve from 1996 to 1999 when Chechnya had de facto independence.

"This is good and long-awaited news," Sergei Yastrzhembsky, a top Kremlin spokesman, said last week after word of the decision leaked.

U.S. officials still contend that many Chechen rebels are waging a purely separatist struggle that can only be resolved by a political solution. "It remains our position that the broader conflict in Chechnya cannot be resolved militarily," said Boucher. "We do not consider all Chechen fighters to be terrorists."

The U.S. government added to its list only three of the most radical groups, saying the leaders of those groups have ties to Osama bin Laden's al Qaeda network or have claimed responsibility for acts that U.S. officials consider to be terrorism.

The Riyadus-Salikhin Reconnaissance and Sabotage Battalion of Chechen Martyrs has about 200 fighters and, according to the State Department, is led by Shamil Basayev.

He has said that he ordered a band of about 50 rebels to take over a Moscow theater in October. In the resulting siege, 129 hostages died, most of them from gas that Russian forces pumped into the theater. All the rebels died.

The other two groups are the International Islamic Brigade -- Basayev also served as a leader of that group until a few months ago -- and the Special Purpose Islamic Regiment, which was headed by Movsar Barayev, who led the theater hostage-takers and died when Russian troops stormed the building.

In a five-page analysis of its decision, the State Department said Basayev and another rebel commander known as Khattab asked bin Laden for help at the start of the second Chechen war with Russia in October 1999. Bin Laden promised the rebel commanders' envoys that he would send money and several hundred fighters, the analysis said, quoting published reports.

It also said that Khattab, sometimes called a protege of bin Laden, sent fighters to Afghanistan in October 2001 to help the Taliban movement that then controlled most of the country. It said many of the Chechens in a select al Qaeda brigade in Afghanistan were likely followers of Khattab, Basayev or Barayev.

Khattab was killed by Russian forces about a year ago. Basayev is said to be hiding in the mountains of southern Chechnya.