Colombia's main leftist rebel group — battered by a years-long government military offensive — says it will seek a cease-fire next month at the start of preliminary talks with the Bogota government.

Thursday's cease-fire announcement by the Revolutionary Armed Forces of Colombia — better known as FARC — comes just days after President Juan Manuel Santos announced a deal with rebels to open talks next month aimed at ending nearly five decades of warfare. The president, however, said there would be no military letup as the talks open in Oslo, Norway.

The FARC cease-fire overture also follows a government announcement Wednesday that another top rebel leader was killed in a government bombing raid this week near the border with Venezuela.

Defense Minister Juan Carlos Pinzon told reporters the rebel was a close ally of the FARC leader known by the alias Timochenko.

“Three guerrillas were killed whose bodies were found. There were 15 weapons seized, [including] explosives, grenades, communications systems. We estimate that at least 15 terrorists may have died. Alias Danilo Garcia, the terrorist right-hand of Timochenko, was killed in the Catatumbo region,” he said.

Last November, Timochenko rose to the rebel group's top post when an earlier leader was killed in a battle with government troops.

An attempt to show good faith ahead of 1999 talks saw an earlier government cede territory the size of Switzerland to rebels. But the FARC used the ceded land to train fighters and build airstrips used to transport illegal drug shipments that financed renewed military operations. Those talks collapsed in 2002.

Ahead of this week's announcement, President Santos repeatedly said he would only consider talks with the FARC if he was certain that rebel leaders would negotiate in good faith. Tuesday, he said Venezuela and Chile will help support the Oslo talks.