Information Minister Eugenio Nse Obiang confirmed that Jammeh was in the country.
Barrow said on Sunday that it appeared his exiled predecessor, Yahya Jammeh, had looted state resources after his election defeat.
Barrow took the oath of office on Thursday at Gambia's embassy in Senegal, calling for international support from West Africa's ECOWAS bloc.
Barrow defeated President Yahya Jammeh in a December election but Jammeh has refused to step aside despite regional pressure
Isatou Toure, a senior Barrow aide, said the mediation effort failed to make any headway but Barrow would be sworn in at some stage on Thurs
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