North Korean leader Kim Jong Un said that an unspecified "crucial" occurrence in the country's war against Covid-19 had sparked a "great crisis" that threatened the isolated nation, a Wednesday report said.

Kim, who was presiding over a Politburo meeting of the ruling Workers' Party of Korea, reprimanded senior officials for failing to implement strong antivirus measures, according to the state-run Korean Central News Agency.

Officials had failed to do their duties, causing the tragedy and "creating a great crisis in ensuring the security of the state and the safety of the people," which "entailed grave consequences," according to KCNA.

Despite testing thousands of people and sharing a porous border with China, North Korea has claimed to have had no coronavirus infections thus far. Given the country's weak health infrastructure, experts broadly mistrust the claim and are concerned about any potential outbreak.

The report said the party also recalled an unnamed member of the Politburo's powerful Presidium, which includes Kim and four other top members.

According to Hong Min, a senior analyst at Seoul's Korea Institute for National Unification, the reference suggested Kim may replace his Cabinet Premier Kim Tok Hun, who would be held accountable for failures in the government's anti-epidemic work.

"There is no possibility that North Korea will ever admit to an infection - even if there were mass transmissions, the North will not reveal such developments and will continue to push forward an antivirus campaign it has claimed to be the greatest," Hong said.

North Korea described its antivirus efforts as a "matter of national existence" from the onset of the pandemic, banning tourists and severely restricting cross-border transportation and trade. The shutdown has stretched an economy that has already been devastated by decades of mismanagement and crushing U.S.-led sanctions over the country's nuclear weapons program.

Earlier this year, North Korea was allocated nearly 2 million doses of vaccines from a global vaccine-sharing program.

However, the plans have been delayed as a result of worldwide shortages.