Updated

The top negotiator for Colombia's main rebel group announced a unilateral cease-fire on Monday, before heading into much-anticipated peace talks with his government counterparts at a convention center in the Cuban capital of Havana.

Ivan Marquez said the Revolutionary Armed Forces of Colombia would stop all military operations and acts of sabotage against government and private property starting at midnight Monday and running through Jan. 20.

Marquez said the move was "aimed at strengthening the climate of understanding necessary for the parties to start a dialogue."

The rebel overture puts pressure on the government of Colombian President Enrique Santos, who has refused to consider a cease-fire during the talks.

There was no immediate response from Santos' government following the announcement, and Colombian negotiators in Havana also refused to comment.

Cuba is playing host to the talks in Havana following an initial round of discussions in Oslo, Norway last month. The FARC has been at war with the Colombian government for nearly half a century. There is no deadline for agreement, though both sides say success must come within months, not years.

The talks, the result of seven months of secret negotiations in Havana, follow several failed efforts over the decades to end the conflict. Land reform, the heart of the conflict, is at the top of the agenda.

The government is hoping peace leads to greater foreign investment in mining industries. It has promised to return millions of acres of stolen land to displaced peasants, one of the rebels' main demands.

The 9,000-strong FARC is being asked as a condition of peace to help end the cocaine trade that has funded its struggle. Colombians also want it to account for the dozens of kidnap victims who have disappeared in its custody and other noncombatants it is accused of killing.