Updated

West African leaders at a summit in Nigeria are discussing the Gambian president's refusal to accept electoral defeat. Military intervention is among options.

Longtime ruler Yahya Jammeh conceded defeat in the Dec. 1 polls, then changed his mind and called for new elections. The United Nations, the United States and leading West African countries have condemned him.

On Saturday, the chair of the Economic Community of West African States, Liberia's President Ellen Johnson Sirleaf, urged leaders to decide "measures to bring this matter to successful conclusion before Jan. 19," when Jammeh's mandate expires.

Community president Marcel de Souza said Friday a military intervention must be considered if diplomacy fails to persuade Jammeh to step down.

He seized power in a 1994 coup and is accused of gross human rights abuses.