SEOUL, South Korea (AP) " North Korea has cancelled one of the key joint cooperation projects with South Korea planned for next month's Winter Olympics, officials said, further proving the delicate nature of ties between the rivals split for seven decades.

North Korea on Monday night sent a message saying it won't hold a joint cultural event at the North's Diamond Mountain on Feb. 4 to mark the Winter Olympics in Pyeongchang, South Korea, according to Seoul's Unification Ministry.

The ministry cited North Korea as saying it has no other option but to cancel the project because of South Korean media reports that it says defamed its "sincere" measures for the Olympics. The North also accused South Korean media of picking a fight over an unspecified domestic festival in North Korea, according to the ministry statement.

The statement said South Korea considers the North's decision "very regrettable."

The North didn't say which media reports were at issue. But some reports had criticized the North's plan to stage a major event to mark the 70th anniversary of the founding of its military on Feb. 8, just one day before the Olympics' opening ceremony. South Korean officials have said the North plans a massive military parade on the anniversary.

It's not clear how the latest development would affect other planned Olympics-related cooperation projects between the Koreas. They agreed to field a joint women's hockey team and have their athletes parade together under a single flag during the Feb. 9 opening ceremony. A dozen North Korean hockey players arrived in North Korea last week to practice with the South Korean players.

North Korea has a history of last-minute cancellations and unexplained reversals, and some experts say it might have sought to gain concessions from the South. The visit earlier this month of a prominent band leader to inspect artistic venues in the South was delayed by North Korea but eventually took place.

The Koreas' current reconciliation mood followed a year of heightened animosities over North Korea's nuclear program. Many analysts say the North may want to use improved ties with South Korea to weaken U.S.-led pressure and sanctions on the country.

SEOUL, South Korea (AP) " North Korea has cancelled one of the key joint cooperation projects with South Korea planned for next month's Winter Olympics, officials said, further proving the delicate nature of ties between the rivals split for seven decades.

North Korea on Monday night sent a message saying it won't hold a joint cultural event at the North's Diamond Mountain on Feb. 4 to mark the Winter Olympics in Pyeongchang, South Korea, according to Seoul's Unification Ministry.

The ministry cited North Korea as saying it has no other option but to cancel the project because of South Korean media reports that it says defamed its "sincere" measures for the Olympics. The North also accused South Korean media of picking a fight over an unspecified domestic festival in North Korea, according to the ministry statement.

The statement said South Korea considers the North's decision "very regrettable."

The North didn't say which media reports were at issue. But some reports had criticized the North's plan to stage a major event to mark the 70th anniversary of the founding of its military on Feb. 8, just one day before the Olympics' opening ceremony. South Korean officials have said the North plans a massive military parade on the anniversary.

It's not clear how the latest development would affect other planned Olympics-related cooperation projects between the Koreas. They agreed to field a joint women's hockey team and have their athletes parade together under a single flag during the Feb. 9 opening ceremony. A dozen North Korean hockey players arrived in North Korea last week to practice with the South Korean players.

North Korea has a history of last-minute cancellations and unexplained reversals, and some experts say it might have sought to gain concessions from the South. The visit earlier this month of a prominent band leader to inspect artistic venues in the South was delayed by North Korea but eventually took place.

The Koreas' current reconciliation mood followed a year of heightened animosities over North Korea's nuclear program. Many analysts say the North may want to use improved ties with South Korea to weaken U.S.-led pressure and sanctions on the country.