Jammeh went into exile in Equatorial Guinea on Saturday after ruling the Gambia for 22 years.
A West African regional force had been launched to remove him but paused to allow for negotiations mediated by Guinean President Alpha Conde and President Mohamed Ould Abdel Aziz of Mauritania.
Diplomats and government sources say Jammeh used that time to try to negotiate immunity from prosecution for alleged abuses and, according to an advisor to Barrow, also loaded up a cargo plane with luxury goods.
Jammeh denied allegations of torture and killing opponents while in power. But his repressive rule and a flagging economy saw thousands flee across the Sahara and Mediterranean to Europe each year.
He's believed to have acquired a vast fortune, including a fleet of Rolls-Royces and an estate in a wealthy suburb of Washington during his rule.
