TOKYO — The United Nations-backed global vaccination effort is offering a new allocation of coronavirus vaccine to North Korea, one of a few countries yet to start inoculating residents after a delay in a distribution program slated to begin this summer.

The Gavi Alliance, part of the Covax initiative that aims to deliver vaccines to the world’s most vulnerable people, said last week that it has allocated nearly 3 million doses of the Chinese-made Sinovac vaccine to North Korea. The announcement came after plans to deliver nearly 2 million doses of the AstraZeneca-Oxford University vaccine were scrapped, amid North Korea’s apparent concerns about potential side effects and a supply shortage at an India-based distributor.

Efforts to provide vaccines to North Korea have reached a bottleneck in recent months. Pyongyang requested vaccine access from Gavi in December, but no doses have been shipped.

It is unclear whether the nation of 25 million will accept the latest offer, Edwin Ceniza Salvador, the World Health Organization’s representative to North Korea, said in a statement. The new allocation was first reported by NK News and Radio Free Asia.

North Korea has completed some of the required steps for accepting the deliveries, such as developing a national vaccine ­deployment program, Salvador said. But technical issues still need to be resolved, such as ensuring that proper storage and delivery systems are in place and negotiating whether North Korea is willing to indemnify the vaccine manufacturer against unexpected side effects, Salvador said.

Meanwhile, a U.N. Security Council panel last week approved sanctions exemptions to allow the shipment of covid-related medical equipment to North Korea.

North Korea claims that it has no coronavirus cases, but it has nonetheless taken extreme measures to restrict outside contact.

The country has sealed its borders to trade and visitors, and has suspended most cargo shipments by land from its major trading partner, China.

Most diplomats have left the country because of covid restrictions, and most aid groups are no longer on the ground. Even the U.N. children’s agency, or ­UNICEF, which is providing technical support to coordinate vaccine distribution, does not have international staff members operating in the country.

The last shipment of non-coronavirus vaccines to North ­Korea was in the second quarter of 2020, according to UNICEF, meaning the country now faces a lag in its routine vaccination program.

North Korea last year experienced its worst economic slump in more than two decades as disasters compounded the impact of the border closure. Floods and typhoons have caused significant damage to its infrastructure and crop yields, and this summer’s heat wave and drought have exacerbated a food shortage.

Accepting vaccine shipments would signal a significant step toward reopening and a shift in North Korea’s overall covid-19 strategy, experts say.

“In order to receive vaccines from outside, North Korea will have to accept aid workers into the country, but this could be a sensitive issue for the secretive country,” said Lee Sang-keun, a researcher at Seoul’s Institute for National Security Strategy, which is affiliated with South Korea’s intelligence agency.

Lee said North Korea rejected the British-Swedish AstraZeneca vaccine because of concerns over rare side effects. He added that Chinese and Russian vaccines are now on North Korea’s radar, and that the regime has expressed interest in accepting doses from Moscow if the Russians would provide them at no charge.

There are no signs that North Korean leader Kim Jong Un has been vaccinated, South Korean opposition lawmaker Ha Tae-keung told reporters in early July, after a briefing by intelligence officials.

Meanwhile, South Korea is looking into helping with vaccine distribution. South Korea’s Unification Ministry spokesman Cha Deok-cheol said in a briefing last week that “direct cooperation between South and North as well as global cooperation are both possible options.”

North Korea has shown it has the capacity to take on national vaccination programs — including a 2007 measles vaccine ­campaign during which an average of 3.3 million people were inoculated a day, according to a report published this month by 38 North, a research program of the Stimson Center think tank.

The country has also demonstrated it can effectively seal its borders to stamp out infectious diseases through strict quarantine measures, said Kee Park, a global health expert at Harvard Medical School who has worked on health-care projects in North Korea and co-authored the 38 North report.

“In some ways, their strategy is, ‘Look, we can keep our shutdown as long as we need to,’ and it’s working,” Park said. “From North Korea side, they’re thinking, ‘Do we really want these vaccines?’ There’s that vaccine hesitancy. They’re not desperate, saying, ‘We want vaccines right now.’ ”

While the country is probably not in a rush to accept vaccines that are still being developed, Park said he hopes North Korea would recognize the long-term benefits of inoculation, especially given the economic pressures it faces.

North Korean state media have warned of a lengthy battle with coronavirus and said that vaccines are “never a universal panacea.”

North Korea has praised other countries’ efforts to develop vaccines, and it has criticized the “national egoism” of countries that officials said were contributing to a global shortage of doses.