Story highlights The threat appeared on the official government newspaper

Tensions between the two nations have grown in recent week

(CNN) Joint US-South Korean military drills are underway Monday despite warnings from North Korea a day earlier that they could lead to a "uncontrollable phase of a nuclear war."

The 10-day Ulchi Freedom Guardian military exercises are conducted annually and touted by South Korea and the United States as defensive in nature.

But North Korea sees them as provocative and hostile, perhaps even preparation for an invasion.

"The Trump group's declaration of the reckless nuclear war exercises against the DPRK ... is a reckless behavior driving the situation into the uncontrollable phase of a nuclear war," North Korean state-run newspaper Rodong Sinmun said, using the acronym for Democratic People's Republic of Korea, the nation's official name.

The piece went on to say that the North Korean army can target the United States anytime, and neither Guam, Hawaii nor the US mainland can "dodge the merciless strike."

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