North Korean leader Kim Jong Un’s powerful sister warned Tuesday that if South Korea launches a preemptive assault, North Korea would use its nuclear weapons to “eradicate” its army.

Kim Yo Jong’s threat, which was published by official media, was her second venomous reaction in three days to comments made by South Korean Defense Minister Suh Wook last week.

“In case South Korea opts for military confrontation with us, our nuclear combat force will have to inevitably carry out its duty,” warned Kim Yo Jong, a prominent strategic advisor in Pyongyang.

It come at a time when North Korea has restarted its sanction-breaking weapons tests in record numbers this year, including the launch of its first intercontinental ballistic missile at full range since 2017.