FARC

"War is always more costly than peace," he said in an interview with the BBC.

Mr Santos and Farc leader Timoleon Jimenez, known as Timochenko, will sign a historic peace deal later on Monday.

But it will take a long time for Colombian society to recover from more than five decades of conflict, he said.

"We could have grown between 2% and 3% more per year for the past 23 years," said Mr Santos.

The conflict has also had a profound impact on Colombian society, Mr Santos told the BBC's Lyse Doucet.

Fresh off his personal appeal to the U.S. and Cuban leaders to end their half-century of estrangement, Francis issued his plea to Colombia's warring factions from Revolution Plaza at the end of his Sunday Mass. Cuba has hosted peace talks for more than two years between the Revolutionary Armed Forces of Colombia and representatives of Bogota.

Francis said the talks face a "crucial" moment.