SEOUL — North Korea said on Friday that it would not participate in the Beijing Winter Olympics because of the coronavirus pandemic and moves by “hostile forces.”

Its no-show at the Beijing ​Games would deprive South Korea of a rare opportunity to establish official contact with the ​North. Officials from the South had hoped that the ​Olympics would provide a venue for​ official delegates from both Koreas to meet to discuss issues beyond sports.

In a letter hand-delivered on Wednesday to China by the North’s ambassador, the country’s Olympic Committee and its ministry of sports wished Beijing a successful Games even though “the U.S. and its vassal forces are getting evermore undisguised in their moves against China aimed at preventing the successful opening of the Olympics,” according to the North’s official Korean Central News Agency on Friday.

The letter added that although North Korea “could not take part in the Olympics due to the hostile forces’ moves and the worldwide pandemic,” it “would fully support the Chinese comrades in all their work to hold a splendid and wonderful Olympic festival.”

The 2022 Winter Olympics has been hit by a series of diplomatic boycotts from Australia, Britain, the United States and other countries as human rights groups and Western governments have accused China of atrocities in its Xinjiang region.

North Korea called the boycotts “an insult to the spirit of the international Olympic Charter and as a base act of attempting to disgrace the international image of China.”

The North is one of China’s closest allies. It depends on China for most of its external trade while struggling under heavy sanctions imposed by the United Nations for its nuclear weapons development. But its chances of joining next month’s Olympics in Beijing have been cast into doubt in recent months.

In September, the International Olympic Committee suspended North Korea’s national Olympic committee until the end of 2022 for skipping the Tokyo Olympiad last year, also because of fears of the coronavirus. But the committee had left the door open for individual North Korean athletes to participate.

North Korea has maintained some of the world’s toughest restrictions to guard against the spread of the virus. It has rejected outside aid and shut its borders, reportedly placing its guards there under “shoot to kill” orders. The country has claimed no Covid-19 cases, and it has rejected offers of millions of vaccine doses, leaving its population vulnerable to explosive outbreaks should its borders reopen.

Officials in South Korea had hoped the Beijing Olympics could provide a venue where officials from the United States, China and the two Koreas could meet. In one of his last diplomatic initiatives before leaving office, set for May, President Moon Jae-in of South Korea has been urging those countries to join his government in declaring an end to the Korean War as an incentive for the North to denuclearize.

But that dream has suffered setbacks as top American officials have shunned the Games and North Korea has called the South’s proposal premature.

North Korea first showed up at the Olympic Summer Games in 1972 and has since participated in every Summer Games, except when it joined the Soviet-led boycott of the 1984 Summer Olympics and when it boycotted the 1988 Games hosted by rival South Korea. North Korean athletes have won 16 gold medals, mostly in weight lifting, wrestling, gymnastics, boxing and judo.

The 2018 Winter Olympics, held in the South Korean city of Pyeongchang, helped bring the two Koreas together. Kim Yo-jong, the only sister of North Korea’s leader, Kim Jong-un, became the first member of the Kim family to cross the border into South Korea to attend the opening ceremony.

Mr. Kim used the North’s participation in Pyeongchang ​as ​​a signal to start diplomacy after a series of nuclear and long-range missile tests. Soon, inter-Korean dialogue followed, leading to three summit meetings between Mr. Kim and Mr. Moon. Mr. Kim also met with President Donald J. Trump three times.

But since the collapse of Mr. Kim’s diplomacy with Mr. Trump in 2019, North Korea has shunned official contacts with South Korea or the United States. The pandemic has deepened its diplomatic isolation and economic difficulties. ​On Wednesday, it launched what it called a hypersonic missile.