Thai forces have driven intruding Vietnamese troops back into Cambodia from the southeastern province of Trat after a two-week operation using air strikes, artillery and ground troops, the Thai military reported today.

The military said the last of up to 1,200 Vietnamese troops who crossed the border late last month and dug into three hills about a mile inside Thailand were dislodged over the weekend. Since the Thai operation to repel the Vietnamese began May 4, Vice Adm. Prasert Noikhamsiri told reporters in the provincial capital of Trat, eight Thai troops were killed, 60 were wounded and 70 were stricken with malaria.

So far, the bodies of eight Vietnamese soldiers have been found on Thai territory, Prasert said.

The Vietnamese incursion reflected Hanoi's apparent determination to cut off infiltration routes used by Cambodian resistance groups, notably the communist Khmer Rouge, to carry on a six-year-old war against the Vietnamese occupation of Cambodia.

The response to the incursion appeared to reflect an equal Thai determination to resist any violation of its territory. Thailand also clearly has an interest in the Cambodian resistance groups' efforts to keep their supply lines open.

Whether Thailand's claimed success in repelling the Vietnamese will affect the guerrillas' supply situation significantly remains unclear, however. As part of a major effort to seal the border, the Vietnamese have poured troops and equipment into the area opposite Trat Province and have press-ganged tens of thousands of Cambodian peasants to build a barricade of fences, ditches and mine fields parallel to the border farther north, opposite the Thai province of Prachinburi.

Prasong Soonsiri, head of Thailand's National Security Council, said the Vietnamese have forced 90,000 to 100,000 Cambodians to work on Hanoi's version of the Maginot Line since late last year, arousing considerable resentment among peasants and spreading a strain of malaria common to the border. Hanoi has insisted that the laborers are "volunteers," but Cambodian refugees have described the dragooning of work teams in various provinces.

The latest border fighting has coincided with heightened concerns about the fate of Cambodian refugees stuck in Thai camps. U.S. officials confirmed today that they would stop interviewing Cambodian refugees for resettlement in the United States early next month, but said this was because all Cambodian applicants currently eligible for resettlement will have been interviewed by then.

U.S. officials stressed that there had been no change in refugee policy and that more Cambodians could be considered later when Thai authorities made them eligible for resettlement. Eligible now are about 20,000 Cambodians residing legally at the Khao-i-Dang refugee holding center near the Thai-Cambodian border.

Excluded are up to 4,500 who entered the center illegally after it was officially "closed" by the Thais, and all but a few special cases among the 230,000 Cambodians who fled resistance settlements for "evacuation sites" on the Thai side of the border in the face of Vietnam's latest dry-season offensive.

U.S. officials said suspension of interviewing next month will mean that about 15,000 Cambodian applicants at Khao-i-Dang will have been refused resettlement in the United States for failure to meet U.S. criteria. During the past 10 years, 190,000 Cambodians have left Thailand for resettlement abroad, 124,000 of them to the United States.

The underlying concern in all this is what will happen to the 225,000 Cambodians who have crossed the border in recent months and are now stuck in evacuation sites that seem to be evolving into semipermanent camps, western officials said.

The refugee situation appears to have spurred new efforts to promote a political settlement of the Cambodian conflict, including a Malaysian proposal for indirect "proximity talks" between the three-party Cambodian resistance coalition and the Vietnamese-installed government in Phnom Penh. The proposal is scheduled to be discussed by representatives of the coalition and the six-member Association of Southeast Asian Nations in Bangkok next week.

In general Thailand has been showing greater self-confidence in its ability to handle the border situation, particularly Vietnamese forays into Thailand, western and Thai officials said.

Thai forces did not hesitate to throw U.S.-supplied fighter-bombers, heavy artillery and Thai marines into the battle against the latest Vietnamese incursion in Trat Province, they said. Yet the incursion aroused no particular alarm here, much less the fear and worry that greeted the arrival of Vietnamese troops on the Thai-Cambodian border six years ago and incursions that followed.