FREETOWN, SIERRA LEONE, AUG. 15 -- International relief workers who ran Monrovia's last functioning hospital until it was closed last week criticized the U.S. government today as shirking a humanitarian responsibility to protect civilian lives by refusing to intervene in the Liberian conflict.

Lucas van den Broeck, an administator with Doctors Without Borders, a French and Belgian medical relief group, said his workers were in daily radio contact with officials at the U.S. Embassy compound in Monrovia but were given practically no assistance to help stem civilians' suffering despite repeated pleas.

"Every day they say, 'We are your biggest fans. We wish you the best.' But they don't lift a finger to help," van den Broeck said.

About 235 U.S. Marines are stationed at the Monrovia embassy, and 2,100 other Marines are aboard four Navy vessels that comprise a U.S. task force off the Liberian coast.

The force is charged only with rescuing American and other foreign nationals -- more than 200 have been evacuated by helicopters in the last two weeks -- and with protecting U.S. government property. According to a Western analyst, the American military presence in Monrovia -- a city terrorized by rival rebel factions and government soldiers -- currently consists chiefly of Marines with bullhorns ordering people who come too near the embassy compound to leave.

"I'm sure Washington would rather these Marine forces were somewhere else," said a U.S. official in the region.

More than 5,000 civilians have been killed and nearly 350,000 left homeless by the nearly eight-month-old conflict in Liberia, in which government and rebel troops have been accused of slaughtering civilians.

Van den Broeck, who was interviewed during a visit here, said U.S. officials refused frequent requests to provide escorts for hospital personnel and turned down pleas to provide protection at the hospital, where patients and staff were frequently harassed, assaulted and robbed by armed combatants.

The hospital, St. Joseph's, is located in a militarily contested section of the city that is frequently under mortar fire. It is several miles and at least one battle line away from the the U.S. Embassy.

The current U.S. approach to Liberia points up changing American attitudes toward the West African country and its strategic significance, according to U.S. officials in the West African region.

Describing the present U.S. policy, one official said: "Somewhere along the way, we just decided we weren't going to get involved. Period. My impression is that Washington and Congress are absolutely fed up with Liberia."

That feeling seems to derive, according to a Western official in the region, from frustration over the years of providing "billions of dollars for Liberia" and "having nothing to show for it."

During the decade that Doe has been in power, the United States has given Liberia nearly $1 billion in economic and military aid. But despite this assistance, Liberia's economy would have imploded had it not been for a boom in world rubber prices, largely driven by a demand for condoms during the AIDS epidemic, the official said.

"Fundamentally, it is a sinkhole, he said. "It's a morass."

Founded by American blacks more than a century ago, Liberia since then has looked to the United States as a political and cultural mentor. America, in turn, saw Liberia as a traditional ally in Africa and made it the site of a key Voice of America radio transmitter.

"We helped create the state, but the relationship was always like a father to a child," the U.S. official said.

In the last eight months, as the country plunged into civil war and anarchy, Doe frequently called on the United States for help, citing at one point in an anguished letter to President Bush Liberia's traditional role as a "stepchild" of the United States.

"Somebody in Washington just decided it was time not to be Big Daddy anymore," the U.S. official said.

"Whose fault is it? It's ours. . . . It's a classic case of too much paternalism," he said.

The official added, however, that nothing can be solved in Liberia until its citizens decide to address their problems reasonably. For now, he insisted, "Liberians are convinced they have absolutely no responsibility for their own actions."

But van den Broeck criticized this approach, saying, "You don't teach a baby to walk by leaving it on a cliff." He pointed out that much of the suffering of Liberian civilians has been caused by U.S.-supplied weapons wielded by men wearing U.S.-made uniforms.

While the U.S. official acknowledged that "we are reduced to the extreme state where they are committing suicide," he added that "we can't possibly do it all."

For now, the official said, the United States is considering ways to support a planned West African peace-keeping force in Liberia and will continue to conduct evacuations from Monrovia.

"Once this is over," the official promised, "there is no doubt we will be in there with massive humanitarian assistance."

Until then, van den Broeck and his colleagues at Doctors Without Borders will try to continue their work.

"If you can help, you should do so," van den Broeck said, recalling a night last month when government troops killed 600 civilians huddling for safety at St. Peter's Lutheran Church in Monrovia. He and other hospital staffers, fearing that the troops would strike the hospital as well, tried to hide patients.

One little girl was an amputee whose mother and father had been killed. "Will you be my father?" the girl pleaded over and over, the relief worker recalled, shaking his head in resignation. He said he intends to return to Monrovia next week.