WASHINGTON (AP) _ U.S. aircraft had ferried more than 150 evacuees from violence-torn Liberia by early today, and the Pentagon dispatched two warplanes to the area to stand by in case of trouble.

Only 54 Americans were among those evacuated. Most U.S. citizens were unable to get to the U.S. Embassy to be evacuated because of fighting in Monroia, the capital, State Department spokesman Nicholas Burns said.

Despite that, he said, ``We believe all Americans are safe.''

The embassy remained open. Tanks from a West African peacekeeping force patrolled parts of Monrovia after Liberia's warring factions reached a cease-fire to calm four days of fierce fighting and looting.

The cease-fire did not hold, however, and scores of Americans remained barricaded in their homes for safety. ``The situation in Morovia is tense (and) chaotic,'' Burns said.

U.S. officials said 54 of the 168 evacuees who left Monrovia were Americans. The rest were British, Irish, French, Canadian, Australian, Ghanian, Egyptian, South African and Greek, Burns and Army Lt. Col. Mike Wood, a Pentagon spokesman, said.

About 200 others, mostly Westerners, were waiting for rescue. While the United States offered rescue to all foreigners in the West African country, it was not immediately clear whether Liberians also would be helped.

Burns said priority was given to Americans, but all flights so far had room for other nationals who wanted to leave.

About 470 Americans live in Liberia, mostly in the capital and its suburbs. They include 48 employed at the U.S. Embassy. Nobody has been ordered to leave.

``The embassy remains open. The embassy, through their mechanisms, is setting priorities,'' Wood said. ``Currently there is no one waiting for a helicopter seat.''

The 235-mile helicopter journey to Freetown, Sierra Leone, takes about two hours. Other flight are taking evacuees to Dakar, Senegal.

About 60 U.S. troops were in Monrovia assisting with the evacuation and a total of 600 U.S. forces in West Africa and Europe were working on the mission named ``Operation Assured Response.''

The order to evacuate U.S. citizens from Liberia was issued Tuesday night, hours after helicopter flights out of the country had begun.

Although Pentagon officials said the violence in Liberia was not directed at U.S. citizens, the military nevertheless dispatched two AC-130 gunships, large, lumbering prop-driven planes heavily armed with machine guns and highly accurate cannon.

In addition, the U.S. European Command, which is conducting the evacuation, sent three HC-130s, tankers capable of refueling helicopters in midair, two MC-130s which are special operations aircraft, and two basic transport C-130s. Wood said those planes were either in the area or en route to Freetown and Dakar, Senegal.

When combined with the five MH-53 helicopters, a total of 14 U.S. military aircraft were involved in the operation.

The Clinton administration received requests for assistance from scores of non-American foreigners who fled the fighting in Liberia and sought refuge at the U.S. Embassy compound.

Among those who asked for help were citizens of Lebanon, Egypt, Italy, Ireland, Greece, Australia, Sweden, the Philippines, Britain, Germany, Canada and Russia.

State Department spokesman Glyn Davies said Tuesday some have requested evacuation while others have asked for different types of assistance.

He said highest priority will be given to meeting the needs of American citizens. ``That's job one, two and three for American officials out there,'' he said.

``Given the unsettled conditions in Monrovia, the United States government has decided to evacuate American citizens from the Liberian capital to locations outside of Liberia,'' Davies said.

A team of 18 Navy SEAL commandos was flown to Liberia on Tuesday to reinforce security at the U.S. Embassy.

Before Americans began to depart Liberia, there were 110 Americans at the compound and 220 other foreigners. Among the latter were diplomats and representatives of international organizations, among other categories.

Two long-range C-5A Galaxy cargo planes were standing by in neighboring Sierra Leone for possible use, but Pentagon officials said the runways and control tower at the Monrovia airport were too badly damaged to permit use of cargo aircraft.