The president, before his departure, was briefed on the release of the 21 abducted Chibok schoolgirls by the Director-General, Department of Security Services (DSS), Alhaji Lawal Daura.
The president, while expressing delight on the development, assured that negotiation would continue until the remaining girls and other Nigerians abducted by the insurgents were released.
The News Agency of Nigeria (NAN) reports that while in Berlin, Buhari would confer with Chancellor Angela Merkel of Germany on issues of interests between the two nations.
A statement earlier issued by Buhari’s Special Adviser on Media and Publicity, Mr Femi Adesina, said the president would discuss issues of further security cooperation with Merkel.
The president, Adesina said, would also discuss issues on humanitarian situation of Internally Displaced Persons (IDPs) in Nigeria with Merkel.
He said Buhari would discuss issues on the rehabilitation of the North-East as well as on trade and economic relations between both countries.
NAN reports the president, who is being accompanied by Governors Kashim Shettima of Borno, Rochas Okorocha of Imo and representatives of the National Assembly, will meet with President Joachim Gauck.
He is expected back to the country on Saturday.