Washington ? The U.S. military commander in Europe has been ordered to begin planning for possible American intervention in Liberia, officials said Thursday, as President Bush and his advisers weighed diplomatic and military options for responding to the Liberian conflict.

Secretary of State Colin Powell said he was consulting the United Nations and leaders in Africa, and Bush’s National Security Council struggled with the issue for a third day.

Powell spoke of “a severe humanitarian crisis emerging” in Liberia as well as concern for the safety of American diplomats there. He said: “All of these factors are being taken into consideration.”

Options on the table ranged from sending no troops to sending thousands, defense officials said.

Some in the administration have suggested that sending a contingent of several dozen soldiers to the U.S. Embassy in Monrovia and stepping up diplomatic efforts might suffice. In line with that, Bush and other U.S. officials were pressing the effort to persuade Liberian President Charles Taylor to leave the country.

Bush said he would not be rushed into making a decision before he left Monday evening for a five-country African tour. He called anew for Taylor to leave.

“A condition for any progress in Liberia is his removal, his removing himself,” Bush said in an interview with African journalists.

He spoke of America’s “unique history” with Liberia, which was founded by freed American slaves, saying there was “a greater sense of expectations” of U.S. help.