HAVANA (Reuters) - A unilateral ceasefire declared by the Marxist FARC rebels at the start of peace talks with the Colombian government two months ago ended on Sunday after the government refused to join the truce, the rebel group said.

"With pain in my heart, we have to admit that we return to the stage of war that nobody in this country wants," FARC lead negotiator Ivan Marquez told reporters before going into the latest negotiation session aimed at ending Colombia's long, bloody conflict.

(Reporting By Jeff Franks and Marc Frank; Editing by Sandra Maler)