Although the hermit state claimed it successfully kept the virus out for more than two years of the pandemic, experts widely doubt it.
North Korea imposed a nationwide lockdown Thursday to control its first acknowledged COVID-19 outbreak after holding for more than two years to a widely-doubted claim of a perfect record of keeping out the virus.
The size of the outbreak wasn't immediately known, but it could have severe consequences because the country has a poor health care system, and its 26 million people are believed to be mostly unvaccinated.
The official Korean Central News Agency said tests of samples collected on Sunday from an unspecified number of people with fevers in the capital Pyongyang confirmed they were infected with the Omicron variant.
In response, leader Kim Jong Un called for a complete lockdown of cities and counties during a ruling party Politburo meeting and said workplaces should be isolated by units to block the virus from spreading, KCNA added.
Kim said it was crucial to stabilise transmissions and eliminate the infection source as fast as possible while also easing the inconveniences caused by the virus controls.
Kim insisted that the country will surely overcome what he described as an unexpected outbreak because its government and people are "united as one".
'Situation must be serious'
North Korea, which employs one of the world's most restrictive border controls, did not provide further details about its lockdown.
Despite the elevated virus response, Kim Jong Un ordered officials to push ahead with scheduled construction, agricultural development and other state projects while bolstering the country's defence postures to avoid any security vacuum.
The North will likely double down on lockdowns, even though the failure of China's "zero-COVID" approach suggests that approach doesn't work against the fast-moving Omicron variant, said Leif-Eric Easley, a professor of international studies at Seoul's Ewha Womans University.
"For Pyongyang to publicly admit Omicron cases, the public health situation must be serious," Easley said.
"This does not mean North Korea is suddenly going to be open to humanitarian assistance and take a more conciliatory line toward Washington and Seoul. But the Kim regime's domestic audience may be less interested in nuclear or missile tests when the urgent threat involves coronavirus rather than a foreign military."
Many foreign experts had disputed North Korea's previous coronavirus-free claim. But South Korean officials have said North Korea had likely avoided a vast outbreak, in part because it instituted strict virus controls almost from the start of the pandemic.
Early in 2020 — before the coronavirus spread worldwide — North Korea took severe steps to keep out the virus and described them as a matter of "national existence."
It quarantined people with symptoms resembling COVID-19, all but halted cross-border traffic and trade for two years, and is even believed to have ordered troops to shoot on sight any trespassers who crossed its borders.
The extreme border closures further shocked an economy already damaged by decades of mismanagement and US-led sanctions over its nuclear weapons and missile program, pushing Kim to perhaps the most challenging moment of his rule since he took power in 2011.
Few countries successful in keeping out the virus
North Korea had been one of the last places in the world without an acknowledged COVID-19 case after the virus was first detected in the central Chinese city of Wuhan in late 2019 and spread to every continent, including Antarctica.
Turkmenistan, a similarly secretive and authoritarian nation in Central Asia, has reported no cases to the World Health Organization, though outside experts widely doubt its claim.
In recent months, some Pacific island nations that kept the virus out by their geographic isolation have recorded outbreaks.
Only tiny Tuvalu, with a population of around 12,000, has escaped the virus so far, while a few other nations — Nauru, Micronesia and the Marshall Islands — have stopped cases at their borders and avoided community outbreaks.
North Korea's outbreak comes as China — its close ally and trading partner — battles its biggest pandemic outbreak.
In January, North Korea tentatively reopened railroad freight traffic between its border town of Sinuiju and China's Dandong for the first time in two years. China halted the trade last month due to an outbreak in Liaoning province, which borders North Korea.
The North's government has shunned vaccines offered by the COVAX distribution programme, possibly because those have international monitoring requirements.
The Omicron variant spreads much more easily than earlier variants of the virus. Its fatality and hospitalisation rates are high among unvaccinated older people or those with existing health problems.