By Lamin Jahateh | BANJUL

(Reuters) Gambian leader Yahya Jammeh accused West African regional body ECOWAS of declaring war, after it said it was putting forces on alert in case he refused to step down at the end of his mandate this month.

Jammeh, who has vowed to stay in power despite losing a Dec. 1 election to rival Adama Barrow, also promised to defend Gambia against any outside aggression, in a New Year’s speech broadcast on state TV.

The veteran leader initially conceded defeat in the vote, then changed his mind days later – raising fears that regional powers might have to intervene to oust him. His mandate runs out on Jan. 19.

Marcel de Souza, commission president for the Economic Community of West African States (ECOWAS), said last week it had put standby forces on alert.

In his speech, Jammeh decried “the resolution of ECOWAS on the current situation to implement the results of Dec 1, 2016 presidential election by whatever means possible,” apparently acknowledging again that the poll did not go in his favor.

“It is in effect a declaration of war and an insult to our constitution,” he said. “Let me make it very clear that we are ready to defend this country against any aggression … My government will never opt for such confrontation but defending our sovereignty is a sacred duty for all patriotic Gambians.”