PYONGYANG, North Korea – North Korea is calling the use of its national flag in U.S.-South Korean military drills a "grave provocative act" and an insult.
An unidentified Foreign Ministry spokesman said in a statement late Sunday that Pyongyang will continue boosting its nuclear weapons program because of U.S. hostility.
The statement calls the program "an all-powerful treasured sword for preventing a war."
The drills Friday were the allies' biggest since the Korean War. A huge North Korean flag on a hill disappeared behind flames and smoke as South Korean jets and U.S. helicopters fired rockets.
The U.N. Security Council condemned a North Korean rocket launch in April that Seoul and Washington called a cover for a test of banned long-range missile technology. North Korea says it was meant to launch a satellite.