Nigerian President Muhammadu Buhari says he won't demand an apology after British Prime Minister David Cameron called his country one of the world's most corrupt nations.

Cameron is hosting an international anti-corruption summit in London Thursday. At a Buckingham Palace reception Tuesday, a television microphone caught Cameron saying "leaders of some fantastically corrupt countries" were coming.

Cameron referred to "Nigeria and Afghanistan — possibly two of the most corrupt countries in the world."

Buhari, who is due to attend, said Wednesday that "I am not going to demand any apology from anybody."

Speaking at an anti-corruption meeting ahead of the summit, Buhari says he was demanding "return of assets" held in British banks.

He says, "I need something tangible" rather than an apology.