WASHINGTON - As the summit between the United States and Russia opened today at the White House, one topic was sure to gain attention after a statement by Russian President Boris Yeltsin: that American prisoners of war from Vietnam were sent to Soviet labor camps and some might still be alive.

"Our archives have shown that it is true - some of them were transferred to the territory of the former U.S.S.R. and were kept in labor camps," Yeltsin told NBC News yesterday in an interview aboard his presidential jet en route from Moscow to Washington.

"We don't have complete data and can only surmise that some of them may still be alive."

Yeltsin did not provide further details. His spokesman, Vyacheslav Kostikov, said:

"After the Vietnam War, a certain number of (American) military prisoners were in Russia," he told reporters at the Russian Embassy. ". . . The president and the new democratic government are trying to do their utmost to find those people - to find the memory of those people, because most of them, of course, have already died. Nevertheless, when I asked the president, `Do you think that some of these people may still be alive?' he said it's not excluded that some of them are still alive."

The Russian statements appeared to confirm long-standing allegations that some Americans captured by North Vietnam were shipped to the Soviet Union. But they also seemed to conflict with the findings of a joint U.S.-Russian commission on POWs released only last week.

The commission reported that some 23,000 American POWs were interned in the Soviet Union at the end of World War II, but said the only Vietnam-era internees it found were deserters from the U.S. armed forces.

Yeltsin wrote a letter to members of Congress last week with more information about American POWs, including some captured after spy-plane crashes in the Cold War, but he did not mention Vietnam-era prisoners.

The Russian revelations come as President Bush is attempting to win congressional approval of a $24 billion multinational-aid package to Russia.

Earlier this year, two former U.S. intelligence analysts testified to Congress that they believed Vietnam-era POWs with technical specialties were transferred to the Soviet Union for interrogation by the KGB secret police, but the Pentagon has denied having such knowledge.

White House spokesman Douglas Davidson said he did not believe the Bush administration knew of the Vietnam prisoners.

In another development, a Russian official also said yesterday that at least one of the estimated 23,000 Americans who came under the control of the Red Army when it liberated German and Japanese prison camps at the end of World War II may still be alive somewhere in the former Soviet Union.

Gen. Dmitri Volkogonov, head of a special Russian commission on the fate of Americans, said authorities received a letter several days ago from the Ural Mountains saying that an American man was living there.

Boris Yeltsin reveals that a Soviet biological-weapons accident led to an epidemic of anthrax. D 1