North Korean dictator Kim Jong-un urged his government to maintain “maximum alert” against the Chinese coronavirus on Thursday, warning of an “unimaginable and irretrievable crisis” should North Korea ease its stringent virus countermeasures too early, South Korea’s Yonhap News Agency reported Friday, citing North Korean state media.

At a Politburo meeting of the ruling Workers’ Party to discuss North Korea’s coronavirus crisis on Thursday, Kim said vigilance against the virus remained paramount, as outbreaks continue to devastate the country.

“He stressed the need to maintain maximum alert without a slight self-complacence or relaxation on the anti-epidemic front, and rearrange and practice stricter anti-epidemic effort,” the state-run Korean Central News Agency (KCNA) said on Friday.

Kim made “sharp criticism of inattention, onlooking and chronic attitude getting prevalent among officials, and violation of the rules of the emergency anti-epidemic work as this work takes on a protracted character,” KCNA said.

“He repeatedly warned that hasty relief of anti-epidemic measures will result in unimaginable and irretrievable crisis, stressing that all the sectors and units should further strengthen the emergency anti-epidemic work till the danger of pandemic incoming is completely rid of,” the news agency said.

Although North Korea officially claims to have zero coronavirus infections, the country’s swift and drastic countermeasures to prevent the spread of the virus, such as closing its borders and schools and placing thousands of its people under quarantine since January, suggest the country has far more cases than it admits to. In late June, reports indicated that North Korean officials had locked down the country’s third-largest city, Chongjin, due to a coronavirus outbreak there. The government also recently extended its border closures through 2021.

Last month, the U.N. warned that North Korea’s shutting of its borders has caused food insecurity in the country to worsen during the pandemic, with some people reportedly “starving” as a result. Prior to the pandemic, over 40 percent of North Koreans were already considered “food insecure,” with many people in the country suffering malnutrition.

According to Yonhap, Thursday’s meeting was “the second time in three months that the North has convened a politburo meeting to discuss the coronavirus pandemic,” also suggesting that North Korea’s coronavirus outbreak has been much more serious than officials admit.

The meeting made no mention of inter-Korean relations, despite escalating tensions between North and South recently over Kim’s fury at anti-Pyongyang leaflet campaigns sent to the North by activists in South Korea.

Last month, North Korea cut off all lines of communication with the South, blew up an empty liaison office in the border town of Kaesong, and threatened to execute further “military action plans” against South Korea over the leaflet campaigns. Last week, however, Kim abruptly put his retaliatory plans against the South on hold, without providing an explanation for the apparent détente.