KCNA released a commentary by Choe Ju Hyon, whom it called an international security analyst, criticising the exercises as "a trigger for driving the situation on the Korean peninsula to the point of explosion."

"The reckless military confrontational hysteria of the U.S. and its followers against the DPRK is driving the situation on the Korean peninsula to an irreversible catastrophe ... to the brink of a nuclear war," the article said.

It was using the acronym of North Korea's official name, the Democratic People's Republic of Korea.

"Now the international community unanimously hopes that the dark clouds of a nuclear war hanging over the Korean peninsula will be removed as early as possible," it added.

U.S. and South Korean forces have been conducting a series of annual springtime exercises since March, including air and sea drills involving a U.S. aircraft carrier and B-1B and B-52 bombers, and their first large-scale amphibious landing drills in five years.

North Korea has reacted furiously to the exercises, calling them a rehearsal for invasion.

The commentary singled out the air carrier's participation as aimed at stoking confrontation, saying the U.S. revealed its "disgusting true colours as the chief culprit of escalating tension."

It said the allies have gone beyond "the tolerance limit" and Pyongyang will respond by exercising its war deterrence through "offensive action."

"The drills have turned the Korean peninsula into a huge powder magazine which can be detonated any moment," it added.

North Korea has been ramping up its military activity in recent weeks, unveiling new, smaller nuclear warheads, vowing production of more weapons-grade nuclear material and testing what it called a nuclear-capable underwater attack drone.

Last month, it test-fired an intercontinental ballistic missile capable of striking anywhere in the U.S., calling it a response to the allied drills.

(Reporting by Hyonhee Shin; Editing by Richard Chang)

By Hyonhee Shin