The powerful sister of North Korean leader Kim Jong Un has threatened South Korea with nuclear retaliation if provoked after Seoul highlighted its supposed pre-emptive strike capabilities against the North.

In a statement published by North Korea’s state media on Tuesday, Kim Yo Jong called South Korea defence minister Suh Wook’s recent comments about pre-emptive strikes a “fantastic daydream” and the “hysteria of a lunatic”.

She stressed that while North Korea did not want another war on the Korean peninsula, it would retaliate with its nuclear forces if the South opts for pre-emptive strikes or other attacks, which would leave the South’s military “little short of total destruction and ruin”.

It was her second angry retort to Suh’s comments in three days. On Sunday she described the remarks as “reckless” and said the South should “discipline itself if it wants to stave off disaster”.

North Korea has repeatedly warned it would be prepared to use its nuclear weapons when threatened by rivals and has accelerated the development of its military arsenal since Kim assumed the leadership more than a decade ago.

It temporarily suspended long-range and nuclear tests when then-United States President Donald Trump agreed to meet Kim Jong Un for an unprecedented series of summits.

The diplomatic initiative collapsed in 2019 and denuclearisation talks have since been stalled.

Kim now appears to be returning to military brinkmanship in an attempt to extract concessions from the US, with Pyongyang carrying out a flurry of weapons tests this year. Last month the country launched its first intercontinental ballistic missile since 2017 and some experts have said a nuclear missile could be next.

Later this month, North Korea will mark the 110th anniversary of the birth of founder Kim Il Sung, Kim’s grandfather.

Typically, Pyongyang likes to mark key domestic anniversaries with military parades, major weapons tests or satellite launches.

The renewed tension on the peninsula has been a major setback for outgoing South Korean President Moon Jae-in, a dovish liberal who had ambitions for inter-Korean rapprochement.

During a visit to the country’s strategic missile command last week, Suh said South Korea had the ability and readiness to launch precision strikes on North Korea if it discovered the North was planning to fire missiles at South Korea.

Seoul has long maintained such a pre-emptive attack strategy to cope with such threats, but it was highly unusual for a Moon administration official to publicly discuss it.

“In case (South Korea) opts for military confrontation with us, our nuclear combat force will have to inevitably carry out its duty … a dreadful attack will be launched and the (South Korean) army will have to face a miserable fate little short of total destruction and ruin,” Kim said in her latest statement.

South Korea’s government did not immediately respond to her comments. Seoul had issued a low-key response following Kim’s earlier comments on Sunday, urging Pyongyang to refrain from further raising tensions and return to dialogue.

Moon met Kim Jong Un three times in 2018 and lobbied hard to help set up Kim’s first summit with Trump in June that year.

But the diplomacy derailed after the second Kim-Trump meeting in 2019 in which the Americans rejected North Korea’s demands for major sanctions relief in exchange for a limited surrender of its nuclear capabilities.

Moon’s term ends in May, when he will be replaced by conservative Yoon Suk-yeol, who could possibly take a harder line on Pyongyang.