LONDON — It was a bracingly honest assessment, but the timing could not have been more embarrassing: Britain’s prime minister, David Cameron, was overheard telling Queen Elizabeth II that Afghanistan and Nigeria were “fantastically corrupt countries,” and “possibly the two most corrupt countries in the world.”
He made the comments at a Buckingham Palace party on Tuesday, in advance of a summit meeting in Britain on the topic of corruption, and they created considerable awkwardness. (It was coincidentally the same party at which the queen was overheard complaining about rude behavior by Chinese officials during a state visit in October.)
President Muhammadu Buhari of Nigeria said through a spokesman that he was “deeply shocked and embarrassed” by Mr. Cameron’s remarks — but he did not rebut them.
Asked if Nigeria was “fantastically corrupt,” Mr. Buhari responded: “Yes.”
Mr. Buhari, who has devoted himself to rooting out graft in Africa’s largest economy, added, “I am not going to demand any apology from anybody.”
He then turned the tables, in a sense, on the British, asking for their help in securing the “return of assets” that were taken out of Nigeria by corrupt officials and business people and are now held in British banks.
Nigeria was ranked 136th, and Afghanistan 166th, out of 167 countries in Transparency International’s most recent Corruption Perceptions Index.
Mr. Buhari’s anticorruption campaign in Nigeria escalated last fall with the arrests of Diezani Alison-Madueke, a former oil minister, and Olajide Omokore, the chairman of a Nigerian oil company. A former defense minister, Bello Haliru Mohammed, was charged in January with corruption.
Plummeting oil prices have set off an economic unraveling in Nigeria, one of the world’s top oil producers, and the collective anger of a fed-up nation has poured out.
Afghanistan, a poor and war-racked country, has its own problems. It generates 90 percent of the world’s heroin, and the government and insurgents have battled each other for the profits from the drug trade amid recent Taliban advances and out-of-control corruption.
Mr. Cameron — whose main political worry is a vote scheduled for June 23 on whether Britain will remain in the European Union — tried to smooth over the gaffe on Wednesday. Without backtracking, he said Afghanistan and Nigeria had taken “remarkable steps forward” to counter corruption, and praised their leaders for “battling hard” to address the problem.