Nigerian President Muhammadu Buhari has extended his stay in London by a week for a dental treatment, his aide has said.

The president had initially travelled to the UK last week to attend the coronation of King Charles III.

He was scheduled to return to Nigeria this week but will now stay back "at the behest of his dentist, who has started attending to him”.

“The specialist requires to see the president in another five days for a procedure already commenced," presidential spokesperson Femi Adesina said in a statement released on Tuesday night.

The president's extended stay in London has sparked criticism from some Nigerians, who say that he should prioritise domestic issues and address the security challenges facing the country.

Mr Buhari has travelled to the UK on a number of occasions throughout his presidency for undisclosed medical reasons amid speculation about his health.

He is scheduled to hand over to the President-elect Bola Tinubu on 29 May.