The Colombian goverment has rejected an offer for talks from the country's most powerful rebel group.

In a videotaped message released before the appointment of president Juan Manuel Santos, the Revolutionary Armed Forces of Colombia (Farc) leader Alfonso Cano offered to open peace talks with the new government.

"Colombia will never talk with terrorists, that is a lesson we have already learned," Rodrigo Rivera, the defence minister, told local media on Sunday.

"There is no dialogue with those who turn to terrorism."

In a separate interview with local radio, Rivera said that government forces knew where Cano is hiding.

He is "fleeing from the security forces. He has no rest... we are not going to let up," he said.

Conditions

After taking office,  Santos said he would not close the door to talks, but they would have to be "based on the unalterable premise that (the guerrillas) give up arms, kidnapping, extortion, drug trafficking, and intimidation".

The Farc has an estimated 8,000 fighters. Another leftist rebel group, the National Liberation Army, is believed to have some 2,000 fighters.

Colombia has been beset for years by violence involving leftist guerrillas, right-wing paramilitary death squads, and powerful drug cartels.

Santos said on Friday that he did not believe the conditions were ripe for talks with the Farc, and ordered Rivera to press ahead with an offensive against them.

As defence minister, Rivera is in charge of both the armed forces and the national police.