Leaders of the Revolutionary Armed Forces of Colombia (Farc) have called for a permanent ceasefire in the wake of the historic peace agreement forged between the leftist rebels and Colombia.

"I order all our commanders and units and each one of our combatants to definitively cease fire and hostilities against the Colombian state from midnight tonight," said Farc leader Rodrigo Londono.

"Never again will parents be burying their sons and daughters killed in the war," said Londono, who is also known as Timoshenko. "All rivalries and grudges will remain in the past."

Colombian President Juan Manuel Santos signed a decree earlier to halt military operations against Farc, also from midnight Sunday (5am GMT Monday), Associated Press reports.

"The end of the conflict has arrived!" Santos said in a tweet. Farc plans to hold its 10th and last guerrilla conference beginning 13 September where members will vote to dissolve the group. Some 200 representatives from dozens of guerrilla units will travel from all over Colombia to Yari, a town in the Farc-controlled part of southern Colombia.

The cessation of fighting follows the a peace accord reached in Havana 24 August, ending the longest war in the Americas: a 52-year conflict between the leftist rebels of Farc — the Spanish acronym for the Revolutionary Armed Forces of Colombia — and the nation that killed 220,000 people and displaced 5 million.

The peace accord faces a final hurdle in October when Colombians will vote on it.

Under the agreement, Farc guerrillas must turn in their weapons over a six-month period to United Nations-sponsored monitors, quit their jungle camps and gradually reintegrate into Colombian society with the help of government training programs.

As part of the accord, Farc's still unnamed future political movement will be given a minimum of 10 congressional seats — five in the lower house, five in the Senate — for two legislative periods. In addition, 16 lower house seats will be created for grassroots activists in rural areas for which existing political parties won't be allowed to run candidates.

After 2026, the arrangements would end and the former rebels will have to compete for all offices at the ballot box.

Farc leaders and Santos will tout the peace deal to the electorate to win ratification. But some dissension remains among those who believe the pact is too easy on the rebels for years of bloodshed. Under a so-called transitional justice system, all but the worst crimes may be resolved with reduced sentences.

Representatives of Farc and the nation had been working toward a peace settlement for nearly four years. The final stage of the deal began with a temporary ceasefire in June. The much-smaller National Liberation Army remains active in Colombia, although it is also now pursuing a peace deal with the government.