For the first time since the Vietnam War, the government of Cambodia has agreed to return what it says are remains of missing U.S. servicemen for identification and burial in this country, Sen. Charles S. Robb (D-Va.) announced yesterday.

Robb said Cambodian Prime Minister Hun Sen has invited a U.S. military forensics team later this month to examine what appear to be remains of an undetermined number of Americans. According to the State Department, 83 U.S. military personnel are listed as missing or unaccounted for in Cambodia.

A total of 2,302 Americans are listed as missing in Southeast Asia.

Contact between Cambodia and the United States is rare. The Bush administration does not recognize the Communist regime of Hun Sen that was installed by Vietnam, and supports military resistance in Cambodia led by Prince Norodom Sihanouk.

But a State Department spokesman and Robb said yesterday that the agreement to repatriate the remains is "humanitarian" and does not signal any change in relations.

"It would be premature to suggest this is anything more than a humanitarian gesture," Robb said. "Obviously, there's no question that it's a hopeful sign. But nothing more should be read into it."

Richard Boucher, a State Department spokesman, said the agreement "implies neither recognition nor any change in our policy toward Phnom Penh . . . . The cooperative effort being announced is another step in our ongoing efforts to resolve the pressing humanitarian issue."

Robb played a key role in arranging the agreement. He visited Cambodia in February and conferred with Hun Sen and other Cambodian officials.

Because of his efforts, he made the formal announcement at a meeting of the National League of Families of American Prisoners and Missing in Southeast Asia.

Cambodian leaders had previously said their government possessed remains of some Americans, but had spurned repeated efforts by U.S. diplomats and officials of the National League of Families to release them.

Robb renewed the requests to Hun Sen and provided him with files of several Americans missing in Cambodia. After an exchange of letters, Cambodian officials suggested that a U.S. identification team come to the country July 24. Bush administration officials agreed to the visit.

Robb and State Department officials said that while Cambodian officials have provided no details about the remains, "Every indication leads me to believe there are remains of U.S. servicemen in the possession of the Cambodian government," Robb said. "They believe the same thing."

Pentagon officials said identification specialists from an Army center in Hawaii are to go to Phnom Penh for preliminary assessment of the remains. Should further examination be necessary, the remains will be transferred to laboratories in Hawaii.

Ann Mills Griffiths, executive director of the National League of Families, said her group is pleased by the agreement. "Most of these people disappeared in parts of Cambodia controlled by Vietnam, and our expectations for accountability by the Cambodian government are not high," Griffiths said. "But we hope they will fulfill this commitment."