Venezuela and Guyana have agreed to restore their respective ambassadors, President Nicolas Maduro said on Sunday, a first step towards easing tensions that flared after the discovery of oil off the coast of a disputed territory. Maduro withdrew his country's ambassador to Guyana in July after demanding a halt to exploration by Exxon Mobil Corp off the region known as the Essequibo, and in September halted accreditation for Guyana's ambassador to Venezuela.