North Korea warned Sunday that the upcoming US-South Korea military exercises are "reckless behavior driving the situation into the uncontrollable phase of a nuclear war."

Pyongyang also declared that its army can target the United States anytime, and neither Guam, Hawaii nor the US mainland can "dodge the merciless strike."

The messages in Rodong Sinmun, the official government newspaper, come a day before the US starts the Ulchi Freedom Guardian military exercises with South Korea.