LONDON, JUNE 14 -- The senior official in charge of Britain's Hong Kong policy accused the United States today of obstructing a solution to the problem of Vietnamese boat people, and he warned that his government may have to resume forcibly returning many of the refugees to their Communist homeland.

Francis Maude, a minister of state in the Foreign Office here, said the United States stood virtually alone in blocking the involuntary repatriation of boat people, while at the same time rejecting proposals that it take responsibility for the housing and welfare of more than 9,000 of the Hong Kong refugees at U.S.-run camps in Guam or the Philippines.

"The United States has a responsibility it can't evade," Maude said in an interview. "Either it joins the consensus of all other nations and comes back from its present isolation, or it provides an alternative."

He added: "It seems to me a wholly indefensible position to be blocking a consensus which all of those who are suffering from the problem want {and} which everyone else including the United Nations {High Commissioner} for Refugees accepts as the right and humane and decent solution . . . and at the same time to refuse an intermediate solution which would take the brunt off those who bear it at the moment."

The United States and Britain have been at odds ever since thousands of boat people started pouring into Hong Kong from Vietnam last spring and summer. Tens of thousands who fled Vietnam since the Communists defeated the U.S-backed South Vietnamese government in 1975 have filled refugee camps to capacity in neighboring countries.

The flood into Hong Kong is now down to a trickle -- 2,362 so far this year, compared to 23,122 in the first six months of 1989, according to the foreign office. Maude attributed the decrease in part to last December's forced repatriation of 51 immigrants, which he said sent a message to Vietnamese that "there is no prospect for them {in Hong Kong} other than a return trip to Vietnam."

Nonetheless, there are 54,500 boat people crammed into squalid camps in Hong Kong, only 10,529 of whom have so far qualified as political refugees. Most of the rest have to go back, British officials insist, unless the United States or some other country agrees to take custody of them.

Maude said Britain hopes to repatriate nearly 1,000 voluntary returnees this month. But once the pool of voluntary candidates runs out, he said, Britain would begin what he called "involuntary repatriations," and he implied that his government could win Hanoi's acquiescence to the move.

Maude, who travels to Washington next Monday for talks with Bush administration officials on Vietnamese repatriation and other issues, said the boat people amounted to nearly 1 percent of Hong Kong's 5.8 million population -- the equivalent of 2.5 million people in the United States.

The U.S. refusal to allow Vietnamese to be repatriated forcibly is a policy personally endorsed and strongly felt by President Bush, according to diplomatic sources here. They said Maude would get a rough reception in Washington from State Department officials who believe he has been working with governments in such Southeast Asian countries as Malaysia and Thailand to isolate the United States and force it into backing down on the issue.

The same sources say Washington rejected the Guam proposal because it would send the wrong signal to prospective boat people eager to find their way to U.S.-controlled territory. "If anyone was allowed into Guam, it would be an enormous draw," said one source. "You'd immediately have 1,000 boats hit the water in Vietnam."

U.S. officials contend the British approach has led to pressure on the United States that would be better focused on Vietnam itself, whose repressive political conditions and discredited economic policies caused the exodus in the first place.

Maude said he agreed that "none of us think the conditions in Vietnam are wonderful" but added that Britain had received "rock-solid guarantees" from the Vietnamese authorities that those returning there would not be punished for having fled.

Amnesty International, the London-based human-rights group, has criticized the process by which boat people are screened in Hong Kong and designated as political refugees or "economic immigrants." It said some of the latter, who are to be repatriated, should have received refugee status and faced persecution and punishment back in Vietnam.