Nigerian President Muhammadu Buhari has said he will “continue to rest” after returning home from seven weeks of medical leave in the UK.
Speaking to dignitaries in the capital, Abuja, he said Vice-President Yemi Osinbajo will remain in charge.
The 74-year-old flew into an air force base in the northern city of Kaduna from London on Friday morning.
Details of his condition have not been disclosed, prompting calls from the opposition for greater transparency.
The president said he was “feeling much better now” but added that further medical checks would be required.
He did not reveal what he was being treated for.
At the end of his nine-minute speech, Mr Buhari said that he deliberately came back towards the weekend “so that the vice-president will continue and I will continue to rest”.
It will be critical in the next few days that the Nigerian leader demonstrates to the public that he is in robust health and in full command.
Otherwise the rampant speculation over his unspecified medical condition will not go away.
His political opponents are questioning whether the president is fit enough to hold office. A sluggish presidential performance will give them more ammunition.
Comparisons will also be drawn to his Vice-President Yemi Osinbajo who displayed an energy as acting leader in the past few weeks strikingly different to President Buhari’s own style.
The president may be back but for now it is not business as usual.
An official statement on Thursday said President Buhari had left Nigeria for a “vacation, during which he had medical check-ups”.
“The holiday was extended based on doctors’ recommendation for further tests and rest.”
The country is currently suffering from its worst economic crisis in years, following a sharp fall in the price of oil, its major export.
It is the second time in less than a year that Mr Buhari, who won elections in 2015, has sought medical assistance overseas. Last June, he spent nearly two weeks, again in London, for treatment for an ear infection.
Little information has been made public about his latest stay in the UK capital, but he was pictured on Thursday meeting the most senior cleric of the world Anglican congregation, Archbishop of Canterbury Justin Welby.