SEOUL, South Korea (AP) — South Korea’s defense minister says North Korea is making final preparations to conduct its fourth nuclear test.

Ministry officials cite Defense Minister Kim Kwan-jin as telling South Korean journalists Thursday that North Korea could detonate a nuclear device the instant the decision is made.

But the officials say Kim didn’t elaborate on what the final step of those preparations was.

Kim was also quoted as saying that North Korea may hold off on a test for some reason.

North Korea has threatened in recent weeks to conduct a nuclear test to protest what it calls U.S. and South Korean hostility and international condemnation over its rocket and missile tests earlier this year.