SEOUL, South Korea (AP) — South Korea says North Korea has cancelled one of key joint cooperation projects planned for next month's Winter Olympics in the South.

Seoul's Unification Ministry says in a statement North Korea on Monday sent a message saying it won't hold a joint cultural event at the North's Diamond Mountain on Feb. 4.

The ministry cites North Korea as saying it has no other option to cancel the project because of unspecified South Korean media reports that it says defamed its "sincere" measures for the Olympics.

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

It's not clear how the development would affect other planned Olympics-related cooperation projects between the Koreas. They agreed to field a joint women's hockey team and to march together during the opening ceremony.