Yahya Jammeh has agreed to cede power to new leader, he said in an address on state TV.
He steps down after 22 years in power.
Jammeh's successor Adama Barrow told a press conference, 'the rule of fear is over' as he prepares to return to The Gambian after being sworn in as president in neighbouring Senegal on Thursday and
The UN Security Council has unanimously approved a resolution expressing "full support" to Gambia's new President Adama Barrow.
The body is also calling on ex-leader Yahya Jammeh to step down and have condemned his attempts to usurp power from Barrow.
The main opposition has said it is unhappy at the offer of asylum for Yahya Jammeh who had refused to step down as president.
Regional troops have secured the presidential palace in the Gambia's capital but there are fears the former leader has raided state coffers.
It ends a political standoff that briefly saw Yahya Jammeh and Adama Barrow claiming leadership of this tiny West African nation.