North Korea says it has entered `a state of war' with South Korea in the latest of a string of threats that have raised tensions on the Korean Peninsula.
A statement Saturday by Pyongyang said all matters between the sides will be dealt with in a manner befitting war.
Earlier this week, North Korean leader Kim Jong Un ordered his troops to be on a high alert in response to annual U.S-South Korean drills.
He warned his forces were ready "to settle accounts with the U.S." after two American B-2 bombers flew a training mission in South Korea.
South Korea says the latest threat is a follow-up to Kim's order.
Analysts say a full-scale conflict is suicidal for Pyongyang and the threats are aimed at drawing Washington into talks.