The already isolated, nuclear-armed North quickly shut down its borders after the virus was first detected in neighbouring China in January and imposed strict containment measures.

Pak Myong Su, a director of the North’s central emergency anti-epidemic headquarters, insisted that the efforts had been completely successful. “Not one single person has been infected with the novel coronavirus in our country so far,” Pak told AFP.

“We have carried out preemptive and scientific measures such as inspections and quarantine for all personnel entering our country and thoroughly disinfecting all goods, as well as closing borders and blocking sea and air lanes.”

Nearly every other country in the world has reported coronavirus cases. Aside from China, South Korea endured one of the worst early outbreaks.

Recorded cases of infection across 188 countries now exceed one million, and these include 51,718 deaths, according to an AFP tally on Thursday based on official country data and World Health Organization figures.

Experts have warned that North Korea is particularly vulnerable to the virus because of its weak healthcare system, and defectors have accused Pyongyang of covering up an outbreak.

The top US military commander in South Korea, General Robert Abrams, said on Thursday that Pyongyang’s assertion that it had no cases was “untrue”. “I can tell you that is an impossible claim based on all of the intel that we have seen,” Abrams told VOA News.

The North’s military was locked down for 30 days in February and early March over the epidemic, he said. “They took draconian measures at their border crossings and inside their formations to do exactly what everybody else is doing, which is to stop the spread,” he added.