Updated

As the United States considers whether to send troops to Liberia (search), the war-battered country's main rebel movement on Friday threatened a "firefight" with any peacekeepers deployed there before warlord-turned-President Charles Taylor (search) steps down.

Taylor, who is wanted for war crimes in neighboring Sierra Leone, has promised to resign and accept asylum in Nigeria -- but only after an international stabilization force arrives to ensure an orderly transition.

The rebels' strongly worded threat came amid mounting security fears in the capital, where hundreds of war veterans protested Friday outside the U.S. and European Union missions, complaining of attacks against Taylor's followers by opponents emboldened by his expected departure.

The rebel Liberians United for Reconciliation and Democracy has said it would welcome peacekeepers and wants U.S. troops to participate. But if the force comes with Taylor still in place, the rebels said it would only strengthen his ability to hang on to power.

"Any troop deployed before the departure of Taylor must be prepared for a firefight," the group said in a communique.

President Bush, in Africa this week on a five-nation tour, faces growing international pressure to send U.S. troops to Liberia, founded by freed American slaves in the 19th century. Secretary of State Colin Powell has said a decision could come within days.

West African nations plan to send more than 1,500 troops to Liberia within 10 days, Ghana's President John Kufuor said at an African Union summit in Mozambique. The regional economic bloc headed by Kufuor previously said it would contribute 1,000 soldiers in two weeks.

Bush has remained noncommittal, but has pledged not to overextend American forces already heavily involved in Iraq, Afghanistan and Kosovo. He also has repeated his demand that Taylor resign as a first step to restoring peace.

"Taylor's government is widely considered to be on its last legs," the rebels said Friday. "Taylor must leave now -- before any deployment."

As momentum builds against Taylor, about 500 Liberian veterans -- many of whom fought with him in Liberia's last civil war, which lasted from 1989 to 1996 -- protested noisily Friday outside the U.S. and European missions in Monrovia.

The former fighters, some on crutches or in wheelchairs, appealed to the United States to help create a unified army to fill the void if Taylor steps down. At least four veterans have been seriously assaulted in the past week in the increasingly restive capital, members of the veterans' association said.

They also demanded that charges be dropped against Taylor -- "for the sake of peace," said Bobby Moore, a 42-year-old army medic. "If they aren't ... there will be more bloodshed than there has been before."

The United Nations (search) and European leaders have sought U.S. troops to enforce a repeatedly violated June 17 cease-fire between forces loyal to Taylor and rebels surrounding his capital. Under the deal, Taylor promised to step down, clearing the way for a transitional government that would oversee fresh elections.

The U.S. European Command, which is responsible for military operations in west Africa, has sent the commander of its special operations branch, Brig. Gen. Gary M. Jones, to Liberia to take charge of the advisory team. Jones was in Liberia and neighboring countries in late May and early June as part of American preparations for a potential evacuation mission.

Another part of the team was in nearby Ghana on Friday to meet with officials from the West African regional bloc, ECOWAS, about their planned deployment to Liberia. More advisers from U.S. European Command were expected to arrive in Accra late Friday to join the talks.