ABUJA, Sha'ban 15, 1436, Jun 2, 2015, SPA -- Nigeria's new president, Muhammadu Buhari, will embark on his first official trip overseas this week when he travels to neighbouring Niger and Chad, his spokesman said on Monday. The spokesman, Garba Shehu, told Reuters that Buhari would visit both countries on Wednesday for talks with his counterparts. --SPA 02:23 LOCAL TIME 23:23 GMT www.spa.gov.sa/w