The World Health Organization has cast doubts on North Korea's claims of progress in the fight against a COVID-19 outbreak, saying it believes the situation is getting worse, not better, amid an absence of independent data.

North Korean state media has said the COVID-19 wave has subsided, after daily numbers of people with fever topped 390,000 about two weeks ago.

Pyongyang has never directly confirmed how many people have tested positive for the virus but experts suspect underreporting in the figures released through government-controlled media, making it difficult to assess the scale of the situation.