Bogota, December 20 (teleSUR-RHC)-- The United Nations has welcomed the FARC's (Revolutionary Armed Forces of Colombia) declaration of an indefinite unilateral ceasefire in Colombia, and offered to help oversee it –- if both parties involved agree.

The rebel group called the indefinite ceasefire earlier this week in Havana, at the end of the last round of peace negotiations for the year. The FARC and the Colombian government have been engaged in peace talks since November 2012 to end the 50 years of civil war in the country. Although unilateral ceasefires have been called in the past, this is first time that no time limit has been set, leaving many optimistic that the two sides may be approaching an agreement.

One of the conditions for the ceasefire set by the FARC was that the situation be monitored by an outside body. On Thursday, the Union of South American Nations (UNASUR) announced that they were open to overseeing the ceasefire. The leftist fighters also approached the Community of Latin American and Caribbean States (CELAC), the International Committee of the Red Cross and the Broad Front for Peace to monitor the ceasefire.

Colombian President Juan Manuel Santos welcomed the ceasefire, however he has refused to agree to it, stating fears that rebels would use the time to recalibrate and acquire arms. The President has also refused to meet the FARC’s conditions for an outside monitoring body, saying the government itself could monitor the situation.

According to the FARC, the ceasefire – which took effect at midnight on Saturday – must lead to a truce, and will only call it off if Colombian soldiers directly attack FARC troops.