North Korea has lashed out in condemnation of the US and South Korea’s five days of joint war drills which kicked off Monday, which mark the largest ever of the annual joint ‘Vigilant Storm’ exercise.

The north vowed to take “all necessary measures” to defend itself, while also claiming that the joint aerial drills are in preparation for a nuclear strike on the DPRK, with a statement from a foreign ministry official cited in KCNA describing “an aggression-type war exercise with the basic purpose of hitting strategic targets of the Democratic People’s Republic of Korea,” which presents the risk of “serious confrontation with great powers.”

“Nowhere in the world can we find a military exercise with an aggressive character like the joint military exercise held by the United States and its followers in terms of duration, scale, content and density,” the foreign ministry official continued. “The US nuclear war script against the Democratic People’s Republic of Korea has entered the final stage,” the official claimed, as cited in Russian media.

The drills include about 100 American warplanes and 140 South Korean aircraft, additionally with Australian assets participating. The Pentagon has said it was “designed to practice wartime missions, roles and tasks in effort to enhance the combat readiness and survivability of US and [South Korean] forces.”

A North Korean Foreign Ministry stated further, “The situation in the Korean Peninsula and its vicinity has entered the serious confrontation phase of power for power again due to the ceaseless and reckless military moves of the US and South Korea.”

The ministry then warned that “if the US continuously persists in the grave military provocations, the DPRK will take into account more powerful follow-up measures.”

Seoul and Washington have been warning since the summer that the north is undergoing preparations for a nuclear test, which would be the first since 2017.

Last week, South Korean President Yoon Suk Yeol briefed his parliament on what he described as imminent plans for such a first nuclear test in five years. “We assess that it has already completed preparations for a seventh nuclear test,” he said Tuesday. He reminded lawmakers that Kim Jong-un has already justified the preemptive use of nuclear weapons, making a test if carried through a severe threat to Seoul’s as well as the broader region’s security.

White House national security official John Kirby has also lately reiterated the US intelligence belief that the north “could conduct a nuclear test at any time.”