The Colombian government's chief negotiator in peace talks with the FARC, Humberto de la Calle, offered his resignation Monday after voters narrowly rejected a peace deal with the rebels.

"Any mistakes we made are my responsibility alone," he told journalists at the presidential palace. "As a result, I have come to tell the president (Juan Manuel Santos) that I am offering to stand down as head of the delegation, because I will not be an obstacle to what comes next."