By Felix Onuah
ABUJA (Reuters) - Nigeria's President Muhammadu Buhari has told parliament that he has resumed his duties following seven weeks of medical leave in Britain, his spokesman said on Monday.
Shortly after returning from London on Friday, the 74-year-old former general said he was feeling "much better" but wanted to rest over the weekend, raising questions about his ability to run Africa's biggest economy and most populous nation.
Nigeria's economy shrank 1.5 percent in 2016, its first full-year contraction for 25 years, largely due to low oil prices and attacks on energy facilities in the OPEC member's Niger Delta oil hub last year.
Buhari had made his deputy Yemi Osinbajo acting president during his absence. The vice president, a lawyer who is seen as more business-friendly than Buhari, played an active role in driving policy changes during the president's absence.
Both men were seen by a Reuters reporter walking together at the presidency offices on Monday.
A statement from the president's spokesman, Femi Adesina, quoted from Buhari's formal letter to the Senate and the House of Representatives, saying: "I have resumed my functions as the President of the Federal Republic of Nigeria."
Buhari first led the country from 1983 to 1985 after taking power in a military coup, and was elected two years ago. Since then he has travelled to Britain several times to consult doctors. Details of his condition have not been disclosed.
(Additional reporting by Alexis Akwagyiram and Ulf Laessing; Editing by Louise Ireland)