Colombia's president threatened to extradite a captured Marxist rebel leader to the US for trial on drug charges if the guerrillas don't free dozens of hostages, including three Americans and a German, by the end of the year.
Ricardo Palmera, a top commander of the Revolutionary Armed Forces of Colombia, or FARC, would become the first member of the rebel group ever sent to face US justice. He is wanted by a federal court in New York on cocaine trafficking charges.
President Alvaro Uribe on Friday signed Palmera's extradition orders after winning approval from Colombia's Supreme Court, but is ready to revoke the decision if the FARC releases the hostages before Dec. 30, his office said in a statement.
Uribe issued a list of 63 captives, including politicians, soldiers, police officers, as well as the three US defense department contractors and a German businessman.
The FARC had no immediate reaction.
The group has said it will only release the hostages in exchange for hundreds of imprisoned guerrillas, Palmera among them, and analysts doubt the FARC would cave in to Uribe's ultimatum.
"The FARC won't accept this type of deal because it would give the impression that they are giving in to government pressure," said Roman Ortiz, a terrorism expert at Los Andes University in Bogota.
Relatives immediately denounced Uribe's move, saying it undermined efforts to reach a deal on a prisoner swap and could prompt the FARC to retaliate with an ultimatum of its own, putting the hostages' lives in danger.
"It's inhumane that both the FARC and the government use hostages in their political and military wrestling match," said Angela de Perez, the wife of a Colombian senator abducted by the FARC three and half years ago.
Uribe on Saturday defended his decision, saying "the government had two options: simply order the extradition [of Palmera] or explore a possibility for the release of the hostages."
"For the good of Colombia, the government once more took a step and chose this ultimatum," Uribe told reporters during a visit to the southeastern city of Popayan.
Uribe has been more flexible with right-wing paramilitary group leaders who have waged a two-decade dirty war against the leftist rebels. On Thursday Uribe pledged to not extradite Salvatore Mancuso, the supreme commander of Colombia's outlawed United Self-Defense Forces, or AUC, provided he ceases all illegal activities and disbands the group.
In related news, some 550 far-right paramilitary fighters turned in their arms on Saturday, the fifth disbandment in less than a month under the country's peace initiative.
More than 3,000 paramilitary combatants have laid down their arms since the middle of last year when the government's paramilitary pacification program began.
In Saturday's demobilization ceremony held in the western province of del Valle, Hernan Hernandez, commander of the paramilitary Calima Block, asked forgiveness "for all the errors we have committed."