The announcement came amid tensions with Seoul and Washington, as US Secretary of State Antony Blinken visits South Korea and after the allies wrapped up one of their major annual joint military training exercises.

The exercises have prompted angry retorts and live-fire drills from nuclear-armed Pyongyang, which routinely condemns all such exercises as rehearsals for invasion.

This time, Blinken's visit appeared to be adding fuel to the fire. The artillery drills were announced a day after Seoul said the North fired three short-range ballistic missiles, described by analysts as a calculated move to grab attention during Blinken's stop in the South.

The drills involved "super-large multiple rocket launchers," according to a report from the state-run KCNA news agency.

When the order was given, it said, the soldiers "simultaneously fired the gun of annihilation".

"Massive shells of super-large multiple rocket launchers, which were fired from the sharp gun barrels like lava, flew to the target with the flame of annihilating the enemy," it said.

The drills also featured a simulation of an "air explosion of a shell of" a super-large multiple rocket launcher, the report continued.

Blinken is attending the third Summit for Democracy and met with President Yoon Suk Yeol in Seoul early Monday. He is also meeting his South Korean counterpart on the sidelines of the event, for discussions now likely to be dominated by the allies' efforts to counter threats from the North.

Seoul is one of Washington's key regional allies, and the United States has stationed about 27,000 American soldiers in the South to help protect it against the North.

Pyongyang this month warned that Seoul and Washington would pay a "dear price" over their military exercises, and later announced that Kim had guided an artillery unit it says was capable of striking the South Korean capital.

Monday's ballistic missile test was the North's second this year, after Pyongyang launched one tipped with a manoeuvrable hypersonic warhead on January 14.