Al Qaeda-linked militants in the southern Philippines said they will stick to a Tuesday deadline to behead a Red Cross hostage unless government troops withdraw from the area, raising stakes in the 10-week crisis despite appeals from Pope Benedict XVI and others to free the three captives.

"The decision of the group is to behead if there will be no pullout," Abu Sayyaf commander Abu Ali told The Associated Press in a cell phone text message Tuesday from the militant jungle stronghold on Jolo island.

"There will be no extension of the deadline for the pullout and we have no plan to release any hostage if there will be no pullout," he said.

Interior Secretary Ronaldo Puno said Monday it was impossible for the government to vacate 15 Jolo villages by 2 p.m. Tuesday as demanded by the militants a day earlier. He said there was not enough time and that a wider pullout would leave the island's civilian population exposed to militant attacks.

Puno hinted the government was ready to use force if the militants harm any of the hostages. Some 120 gunmen have held the aid workers — Filipino Mary Jean Lacaba, Swiss Andreas Notter and Italian Eugenio Vagni — in a hilly jungle in Jolo's Indanan town since Jan. 15. Until a recent withdrawal, they were surrounded by more than 1,000 troops.

Conceding to earlier militant demands, the marines withdrew to their camp last week, and police and militiamen moved back from the Abu Sayyaf stronghold by six to nine miles (10-15 kilometers), hoping the group would release one hostage.

But the militants insisted the troops must pull back to two villages near the provincial capital — a demand the government says would lead to anarchy.

At the Vatican on Monday, the pope appealed for the release of the hostages, urging that "humanitarian sense and reason win out over violence and intimidation." He called for authorities to work for a peaceful solution.

The president of the International Committee of the Red Cross reiterated his appeals for the hostages' freedom.

"Our message to Abu Sayyaf is: Please spare and release Mary Jean, Eugenio and Andreas," said Jakob Kellenberger. "All they were doing was helping people in need in your area. There is no ideology or religious law that could justify killing them."

President Gloria Macapagal Arroyo's spokesman, Cerge Remonde, also said he hoped "these bandits have a sense of humanity" and release the hostages.

The hostages were seized after visiting a water project for a jail on Jolo, a predominantly Muslim region about 590 miles south of Manila.

The Abu Sayyaf group has beheaded hostages in the past, including an American in 2001 as well as seven Filipinos in 2007.

The U.S. government has placed the Abu Sayyaf, which has about 400 gunmen, on its list of terrorist organizations.