SEOUL — North Korea reported 2.24 million people “sickened with fever” as of Thursday evening — a big jump from last week when the secretive nation acknowledged its first suspected cases of COVID-19.

North Korean’s state-run Korean Central News Agency is still not referring to the outbreak as COVID-19, likely because there are no test kits to diagnose patients.

South Korea-based analysts who have been closely monitoring the North for the last few decades suggest that the tally revealed by the reclusive regime each day may not be accurate, due to a lack of testing capabilities.

“There is no evidence that North Korea is using PCR test kits to determine COVID-19 patients, so no one outside can say for sure if it’s just fever or COVID-19 symptoms,” Philo Kim, associate professor at Seoul National University’s Institute for Peace and Unification Studies, told ABC News on Thursday evening.

Since the coronavirus pandemic swept across the globe in 2020, North Korea has completely closed off from the outside world in an effort to stop the virus from entering its borders. No international organization has been able to enter the country to precisely determine its medical environment, aside from a few Chinese medical experts.

Analysts believe that Pyongyang will continue to resemble China’s totalitarian approach to the pandemic with further isolation and strict lockdowns, leaving them no choice but to aim for collective immunization.

“The most concerning of all is that there could be so many deaths, so much that is unimaginable,” Dr. Kim Sin-gon, professor at Korea University’s College of Medicine in Seoul, who has taken part in supplying Pyongyang with medical supplies, told ABC News on Thursday evening.

Dr. Jiho Cha, professor at Korea Advanced Institute of Science and Technology’s Moon Soul Graduate School of Future Strategy in Daejeon, agreed.

“It will take time to reach herd immunity either through vaccinations or by having COVID,” Cha told ABC News on Thursday evening, adding that — either way — “a conservative figure would be at least 200,000 deaths.”

Last year, the World Health Organization-led global vaccine-sharing scheme known as COVAX reached out to North Korea to offer nearly 3 million doses of a COVID-19 vaccine made by Chinese biopharmaceutical company Sinovac. An additional 250,000 doses of a COVID-19 vaccine developed by American biotechnology company Novavax were later allotted to North Korea. However, Pyongyang turned down both offers and kept its borders shut instead.

Last week, South Korean President Yoon Suk-Yeol said he intends to provide COVID-19 vaccines and other medical supplies to North Korea, with the endorsement of the United States, but Pyongyang has yet to respond.

“They do not want aid workers to come in and monitor,” Choi Gyubin, research fellow at the Korea Institute for National Unification in Seoul, told ABC News on Thursday evening. “They would also not appreciate foreigners telling who gets the first vaccines in which areas.”

North Korea experts said the nation is likely to continue abiding by its founding philosophy of self-reliance for now, but that its leader Kim Jong Un will have to make a crucial decision soon. After all, COVID-19 cases exploded following North Korea’s massive military parade last month, in which tens of thousands of young citizens attended from around the country. Earlier this week, Kim reprimanded a few officers for failing to deal with the initial phase of the outbreak successfully and professionally.

“[But] the fact is that it was none other than Kim Jong Un himself who should bear the responsibility of being tardy in handling this crisis situation,” Kim Sook, executive director at the Ban Ki-moon Foundation for a Better Future in Seoul and former South Korean ambassador to the United Nations, said during a panel discussion at California’s Stanford University on Thursday.

“Kim Jong Un made a bad bet — a very bad bet,” added Siegfried Hecker, a renowned expert on North Korea’s nuclear program who is currently affiliated with Stanford University.

Given North Korea’s current health situation in which a majority of the people suffer from malnutrition and with almost no vaccines, experts said the repercussions of not moving fast enough could take a dangerous toll on the regime.

“North Korea faces a surge in pandemic patient numbers, even after voluntarily going into strong isolation for the last two years,” Cha told ABC News. “There’s a high chance they won’t be able to prevent the majority of its people from catching COVID-19, even if they force additional lockdowns.”

ABC News’ Eunseo Nam and Hyerim Lee contributed to this report.