President Muhammadu Buhari, 74, came to the UK for treatment for an unspecified illness.
On Sunday, he met governors from his party for lunch and was very cheerful, according to a government statement.
His absence has led to some anxiety in Nigeria, with some speculating that he might have died.
Others have worried he may not be able to return to duty.
The statement said the president “was very cheerful and has not lost any bit of his sense of humour”.
Buhari’s unhealthy start to 2017
19 January: Leaves for UK on “medical vacation”
5 February: Asks parliament to extend medical leave
10 March: Returns home but does not resume work immediately
26 April: Misses second cabinet meeting and is “working from home”
28 April: Misses Friday prayers
3 May: Misses third consecutive cabinet meeting
5 May: Appears at Friday prayers in Abuja
7 May: Travels to UK for further treatment
6 June: Buhari’s wife says he is “recuperating fast”
12 July: Acting head of state says the president will be home “very soon”
