"Since the first day of my administration, I have obeyed the constitutional obligation to seek peace. Towards this direction, we have undertaken exploratory talks with the Farc," Santos said during a press conference Monday.
Santos did not provide any further details about the talks, but Colombia's RNC Radio and Venezuela's TeleSur news station reported that the two parties had signed an agreement during a meeting in Havana to hold peace negotiations in Oslo in October.
If confirmed, this would be the first time formal peace talks were held since 1999 under President Andres Pastrana. The talks ultimately disintegrated after rebels, who had been granted a safety zone during negotiations, continued to carry out kidnappings of and attacks against both government targets and civilians.
The Farc was established in 1964 as a Marxist revolutionary movement. It has become notorious for funding itself through cocaine trafficking and holding hostages for ransom, as well as for engaging in murder, rape, extortion and torture.
Recently, the rebels have suffered substantial military defeats with the loss of key leaders and a decline in membership.
"The Farc knows the time has come to make peace, and the government shouldn't be triumphalist, but knows there is a chance now for the public to accept (negotiations)," Camilo Gomez, chief negotiator under Pastrana, told CNN.
Santos' administration has received some criticism for setting up the talks without securing any agreement from the Farc to halt violent activity.
"The government doesn't seem to have learned from history," Alfredo Rangel, director of the Center for Security and Democracy at Sergio Arboleda University in Bogota, told CNN.
"I think it's problematic that the government started negotiations with this terrorist group without asking first for it to stop all attacks on civilians."
The exploratory talks come two months after Colombian lawmakers approved a bill that would reduce punishment for rebels in exchange for laying down arms.
The bill, known as the Legal Framework for Peace, was intended to encourage the Farc to enter into peace talks, but has been criticized for being too lenient on those rebels who have committed violent crimes.
"The Legal Framework for Peace is essentially an amnesty in disguise," Human Rights Watch said in a statement.
"Colombia's victims will see that if they have to watch their abusers walk free without spending a day in prison."
Nevertheless, the Colombian populace is weary of the conflict, and appears to be veering toward wider approval of peace negotiations and measures that support them.
"What needs to be done is to find a path so all Colombians can put their faith in the construction of a new country," Colombian Senate Leader Roy Barreras recently told reporters, adding that the government needed to proceed with the "prudence and caution."
"For the violent Colombians, this is also an opportunity for social and political reintegration."