Specifics on the number and types of U.S. troops are still to be worked out and approved by President Bush, two officials said. But a directive called a "warning order" was sent overnight to European commander Gen. James Jones, asking him to give the Pentagon his estimate of how the situation in the West African nation might be handled.
Mr. Bush is trying to decide how to respond to international pressure that he send up to 2,000 troops to help enforce a cease-fire in the country, wracked by fighting between forces loyal to President Charles Taylor and rebel groups trying to oust him.
CBS News Correspondent David Martin reports one option President Bush is considering calls for sending about 700 soldiers, under the condition they would come out in a matter of months and be replaced a by U.N. peacekeeping force.
Officials said a plan also is under consideration to send only a small group of troops as a show of interest and to protect the U.S. Embassy.
Some in the administration have suggested that a contingent of several dozen soldiers at the embassy in Monrovia along with stepped up diplomatic efforts might suffice. In line with that, one official said, U.S. officials said they are pressing the effort to get Taylor to leave the country.
Mr. Bush Wednesday repeated his call for Taylor to step down.
"One thing has to happen: Mr. Taylor needs to leave the country," Mr. Bush said. "In order for there to be peace and stability in Liberia, Charles Taylor needs to leave now."
In an interview with CBS Radio on Wednesday, Taylor said he would be willing to leave within 90 days if a peaceful transition could be arranged. Though many say Taylor is not known to be a man of his word.
Other military options are to send 500 to 1,000 Americans who might coordinate logistics for any peacekeeper mission, provide it with communications equipment, further evaluate the situations in Liberia, assist non-governmental organizations there and so on, two officials said.
Taking that role, rather than the lead in a peacekeeping force, would allow the United States to keep down the number of Americans required — a major consideration with so many already deployed around the world for the war against terror and stabilization in Iraq.
Taylor has refused to leave office. A U.N.-backed court in neighboring Sierra Leone has indicted him for crimes against humanity for his backing of rebels in that country, where atrocities included hacking off victims' limbs.
Taylor told CBS Radio that U.S. troops would be welcomed his country, and called for the United Nations war crimes charges against him to be dropped.
He said he was not sure if "asking the democratically elected president to leave is the solution, but I will leave," he said.
"Of course," Taylor added later, "that is subject to hearing what President Bush has to say."
Mr. Bush is under pressure make a decision before he visits Africa next week. The trip doesn't include a stop in Liberia, founded in 1847 by freed American slaves.
Secretary of State Colin Powell has talked a number of times in recent days to U.N. Secretary-General Kofi Annan, who would like to see the United States lead a multinational peacekeeping force. African nations have offered 3,000 troops for such a force.
Besides Annan, France, Britain and both sides in Liberia's fighting also have pushed for an American role. In Washington, the Congressional Black Caucus also called on Powell to persuade the White House to intervene quickly.
Mr. Bush is reluctant to send troops purely as peacekeepers, officials have said, but might be more inclined if the troops were given a clear mission as part of a defined coalition. Besides that, the U.S. military has plenty on its plate without sending troops to Liberia.
More than 10,000 American troops are still working in and around Afghanistan, and nearly 150,000 troops are stationed in a violent and troubled postwar Iraq.
The current round of fighting in Liberia began three years ago as rebels began trying to oust Taylor, who won contested elections. Fighting killed hundreds of civilians in Monrovia just last month, and the war has displaced more than 1 million Liberians.
Because of the violence — but apart from the question of U.S. peacekeepers — several dozen U.S. Marines have for days been on standby at a Spanish military base in case they are needed for quick deployment as extra security at the U.S. Embassy in Monrovia or to evacuate Americans.