The United States is curtailing its Peace Corps program in Russia after a number of the American volunteers assigned to work there were denied visa extensions by the Russian government. The State Department says new volunteers originally destined for Russia will be sent elsewhere.

The Peace Corps has been operating in Russia since 1992 after the collapse of the Soviet Union and to date more than 700 U.S. volunteers have worked there, mainly in business-education and English language programs.

But the program may come to an end soon, with Moscow refusing to extend the visas of about half of the 64 volunteers now in that country, and the State Department saying that because of the problem, a new class of volunteers due to arrive there next month will be sent to other countries.

Officials here and at the Peace Corps say Russian authorities have given no explanation for the visa denials. However a Washington Post report from Moscow quoted a Russian education official as saying the Americans were unqualified for their teaching assignments. It also said there was resentment among some Russian officials about the presence of a U.S. aid program initially designed to help developing countries.

At a news briefing here, State Department spokesman Philip Reeker said Peace Corps workers have proven "very valuable" in a number of formerly-communist Eastern European countries, helping their economic transitions. He insisted those assigned to Russia have been qualified for their roles, but he said if they are not needed there, they can and will work elsewhere.

"I think what I've seen certainly is that our Peace Corps volunteers are very well-qualified in the fields to which they're assigned," he said. "And they're a resource that has been put to use in many countries, as I said, in the region facing a similar economic transition that Russia has had to go through in the past decade. But obviously, if they're not needed in that capacity in Russia, we can reevaluate where we may better deploy that resource, which, as you know, is an important thing that we've offered now for many years, and I think quite effectively, to countries around the world."

A senior official here said he was unaware of any pending diplomatic complaint to Moscow about the treatment of the U.S. volunteers. He also downplayed the notion that the issue has affected the overall U.S.-Russian relationship, which has grown closer in the aftermath of last September's terrorist attacks in New York and Washington.

More than 165,000 Americans have served in the Peace Corps in some 135 countries since the volunteer program was founded by President John F. Kennedy in 1961.