Colombia's Congress on Wednesday passed a law granting amnesty to FARC rebels as part of the country's peace deal, a development the government hailed as "historic."

"Thanks to the Congress which in a historic vote approved the amnesty law, first step toward consolidating peace," President Juan Manuel Santos said on Twitter.

Colombia's Congress has given its stamp of approval to a peace accord aimed at ending a 52-year-old armed conflict with FARC guerrillas -- Latin America's longest -- but experts say implementing it will not be easy.

The lower house of the Congress approved the accord with the Revolutionary Armed Forces of Colombia, or FARC, by a unanimous vote late Wednesday, clearing one of the last legal hurdles for it to go into effect.

Colombia's government and Marxist FARC rebels on Saturday announced a revised peace deal to end 52 years of armed conflict, after voters rejected a prior peace accord in a referendum.

"We have reached a new final agreement to end the armed conflict, which incorporates changes, clarifications and some new contributions from various social groups, which we have gone through one by one," said a joint statement read out by diplomats from Cuba and Norway, the peace process guarantors.

Colombian President Juan Manuel Santos said Thursday a ceasefire with the country's FARC guerillas has been extended until December 31 but that he hopes to have "a new agreement" for peace before that date.

"I have made the decision to extend the bilateral ceasefire until December 31. Let this be clear: This is not an ultimatum nor a deadline, but I hope that the entire process of obtaining a new agreement will be complete well before then," the president said in a televised address.

U.N. chief Ban Ki-moon hailed the awarding of the Nobel Peace Prize to Colombian President Juan Manuel Santos on Friday, saying it shows the country has come "too far to turn back now."

The decision comes "at a critical moment when this special acknowledgement provides needed hope and encouragement to the Colombian people," the United Nations secretary general said about Santos's efforts to bring the country's half-century-long civil war with the FARC rebels to an end, despite voters' rejection of a historic peace deal.

Colombia's President Juan Manuel Santos won the Nobel Peace Prize on Friday for his efforts to end the half-century war with FARC rebels, sparking a new pledge to salvage a peace deal rejected by the people.

The award was a surprise, coming just five days after Colombian voters shot down the historic accord Santos signed last month with FARC leader Rodrigo Londono, alias Timoleon "Timochenko" Jimenez.

Colombian President Juan Manuel Santos said Wednesday peace with the FARC rebels is "close," but his top opponent demanded an overhaul of a "weak" deal rejected by voters in a referendum.

Seeking to salvage the peace process on which he has staked his legacy, Santos held a meeting with his predecessor and former boss, Alvaro Uribe, who has branded him a traitor for negotiating with the Revolutionary Armed Forces of Colombia (FARC).

Colombian President Juan Manuel Santos said Tuesday that a ceasefire with FARC rebels will end on October 31, as both sides scramble to find a solution to the half-century conflict after voters rejected a peace deal.

The chief of the Revolutionary Armed Forces of Colombia (FARC) Rodrigo Londono, better known as Timoleon "Timochenko" Jimenez, promptly took to Twitter to ask "And after that, the war continues?"

The Colombian government and FARC rebels scrambled Monday to save a peace deal after voters narrowly rejected it in a referendum, throwing the four-year-old peace process into uncertainty.

President Juan Manuel Santos, who has staked his legacy on ending the 52-year-old conflict, called an emergency meeting with leaders of the country's political parties to try to chart a way forward after the shock referendum defeat Sunday.

Colombians vote in a referendum Sunday on whether to ratify a historic peace accord to end a 52-year war between the state and the communist FARC rebels.

The accord will effectively end what is seen as the last major armed conflict in the Western Hemisphere. The war has killed hundreds of thousands of people and displaced millions.