Colombian leaders and rebels seeking a historic peace accord sought Pope Francis and UN chief Ban Ki-moon's help Friday in setting up a court to prosecute atrocities committed during the conflict.

The court will be a delicate part of a peace agreement that the government and the FARC leftist rebel group are hoping to sign soon to end Latin America's last armed civil conflict.

They said they had agreed to ask Pope Francis and Ban along with three Colombian judicial authorities to contribute to naming judges to sit on the planned new court, which will be called the Special Peace Jurisdiction.

They made the announcement in a statement read out to reporters in the Cuban capital Havana, where they have been holding peace talks since 2012.

The sides laid the groundwork for a full peace deal when they signed a definitive ceasefire and disarmament agreement in June.

They want that deal to come into force under a further, overall peace accord that they hope to sign in the coming weeks. They also hope Colombians will endorse it in a referendum.

But many Colombians are wary of a deal that they fear could see FARC fighters reintegrated into society without being jailed over the bloodshed.

A poll published on August 7 indicated a majority of Colombians would reject the peace deal in a referendum.

Negotiators say the final peace accord will set up a court to try those accused of the worst atrocities. But some of those accused of less serious deeds could receive an amnesty.

Around 260,000 people have been killed in the territorial conflict in Colombia, which started in 1964.