North Korean leader Kim Jong-un has warned against the "hasty" relaxation of anti-coronavirus measures and has indicated the country will keep its borders closed for the foreseeable future, according to state media reports.

North Korea closed its borders in late January as the virus spread in neighbouring China, imposing tough restrictions that put thousands of its people into isolation.

Pyongyang insists it has not had a single case of Covid-19.

Analysts say the country is unlikely to have completely avoided the virus, and that its health system would struggle to cope with a major outbreak, but Mr Kim told a meeting of the Workers' Party yesterday that North Korea's efforts have been a "shining success", the official KCNA news agency reported.

It cited him as saying: "We have thoroughly prevented the inroad of the malignant virus, despite the worldwide health crisis".

Mr Kim cautioned against any "self-complacence or relaxation", calling for stricter anti-epidemic efforts while "re-infection and re-expansion of the malignant contagious disease persists in neighbouring countries".

South Korea is currently recording around 40 to 60 cases a day, while China saw a surge of infections in Beijing last month.

His comments are an indication that North Korea will maintain its self-imposed blockade, which has also hit trade with China. Several embassies in Pyongyang have temporarily closed as they have been unable to bring in supplies, money and staff.

Under the current rules, any arrivals must spend 30 days in strict quarantine. Diplomats and analysts believe the border could remain closed for the rest of the year.

"It has no choice but to keep its border closed with China, it is something inevitable for the North," said Hong Min, director of the North Korean division at the Korea Institute for National Unification.

"Its border closure with China may harm its economy, but the Pyongyang leadership seems to have determined preventing a coronavirus outbreak is more important in keeping control of the country."