Aziz left Gambia shortly before midnight, when Gambian leader Yahya Jammeh's presidential mandate expired. Senegal, with backing from leaders in the region, has threatened to invade Gambia to depose Jammeh if he does not immediately hand over power to challenger Adama Barrow, who beat him in an election in early December. After the talks, Aziz's plane left Dakar at about 1:45 am(0145 GMT), a Reuters witness saw. Aziz had been talking with Barrow and Sall at the airport in Dakar. About 30 vehicles with tinted windows then sped away from where the talks took place. The Gambian capital Banjul, a city of tourist hotels and sleepy streets shaded by mango trees, was silent apart from the occasional military helicopter buzzing overhead. Facing almost total diplomatic isolation, a government that has all but collapsed from defections and the looming threat of a military intervention by his neighbours, it was unclear what might be Jammeh's next move. 'It is absurd,' Barrow's spokesman said in a press conference on Wednesday. 'The clear position is that the president-elect should assume office on the 19th'. But Jammeh, who took power in a 1994 coup and later vowed to rule for 'a billion years', has so far ignored calls by world powers and regional leaders to step aside and avert a conflict. He says the electoral commission was under the influence of 'foreign forces,' and has challenged the result in a court - which however currently has no judges to preside over it. The African Union and West African regional body Ecowas have both said that as of Thursday they only recognise Barrow as Gambia's president. Barrow was due to be sworn in later on Thursday, but plans to do so at the national stadium could not go ahead. Barrow's spokesman Halifa Sallah said he would be sworn in an undisclosed location. Hours before the deadline for him to hand over, the Senegalese army said it had amassed troops at the border, ready to cross into its smaller neighbour, which it engulfs on all sides, if Jammeh fails to leave power. Gambians celebrated in the streets when Jammeh conceded electoral defeat to Barrow, a real estate developer who once worked as a security guard at an Argos store in London. But a week later, the president changed his mind, triggering international condemnation and threats of force. It was the latest in a long line of eccentricities from a leader who had said only Allah can remove him from office, claimed to have a herbal cure for AIDS that only works on Thursdays and threatened to slit the throats of homosexuals.