U.S. Secretary of State Colin Powell is talking to senior Georgian and Russian officials in an effort to ease tensions in Georgia's breakaway South Ossetia region. South Ossetian separatists have taken some 50 Georgian peacekeepers hostage.

Mr. Powell is using personal diplomacy to try to defuse the latest upsurge in regional tensions in Georgia fueled by the hostage incident in South Ossetia.

The Georgian central government is reported poised to send troops into South Ossetia after separatists, who want the region to secede and join Russia, disarmed a unit of Georgian peacekeepers and put them on display before an angry crowd.

The United States has strongly supported Georgia's new reformist government of President Mikhail Saakashvili and its efforts to keep the country united.

At a news briefing, State Department spokesman Richard Boucher condemned what he termed the "deplorable" treatment of the Georgian prisoners and called on South Ossetian authorities to release them and avoid "further violent provocations."

"We're encouraging all sides to work for the immediate release of the hostages and to take steps to reduce tensions," he said. "We think that intensified dialogue is the best way to a peaceful solution that insures Georgia's territorial integrity and avoids further violence."

Mr. Boucher said Secretary Powell telephoned Georgian Prime Minister Zurab Zhvania to discuss the situation, and later called Russian Foreign Minister Sergei Lavrov.

Mr. Zhvania called the hostage incident unprecedented and said while the Tbilisi government hoped for a peaceful outcome, it had ample strength to stop what he said was the South Ossetian side's aggression.

He also said Russia, the effective protector of the rebel province, was partly responsible for the escalation. The South Ossetian leader Eduard Kokoity was quoted as saying the sides were on the verge of widespread military action.

Secretary of State Powell was also involved in diplomacy that ended a similar standoff this year between the Georgian government and separatists in another region, Ajaria, on the Black Sea.

That confrontation ended in early May when the Ajarian leader resigned and flew into exile in Russia.