Colombia's government and FARC rebels are expected to make an announcement Wednesday concerning a peace deal to end the country's half-century civil war, sources close to the negotiations said.

Over the past few days, the government and the Revolutionary Armed Forces of Colombia (FARC) have been discussing a range of topics that remain unresolved, and worked late into the night Tuesday to draft a joint statement, sources from the two delegations told AFP in Havana.

However, officials contacted by AFP were unable to confirm whether the announcement will mark the conclusion of negotiations, which were initiated in late 2012 in the Cuban capital.

"We hope that it will be announced that the peace talks were successfully concluded," a member of the government negotiating team said, on condition of anonymity.

FARC leader Timoleon "Timochenko" Jimenez tweeted that negotiators were "at the threshold of important announcements to bring a final accord."

Once a peace deal is signed, the FARC will begin calling in its troops for disarmament, under a ceasefire that the United Nations is helping monitor.

The deal must also be endorsed by Colombians in a referendum.

The conflict began in 1964 and is the longest-running war in Latin America, having left at least 260,000 people dead, 45,000 missing and 6.8 million displaced.