The Colombian government and the country's largest rebel group say they are requesting a United Nations observer mission to monitor a cease-fire and disarmament process that would end the Western Hemisphere's longest-running conflict.

Negotiators for the two sides announced at peace talks in Havana Tuesday that they would be request a 12-month, unarmed mission with observers from Latin American and Caribbean countries. They said the mission would guarantee that a cease-fire and disarmament would be genuine and permanent, calling the announcement a "transcendental" moment in the years-long peace talks.