Updated

North Korea has issued its latest nuclear threat, two days after South Korea's defense minister said Pyongyang was making final preparations to conduct its fourth nuclear test.

The North's official Korean Central News Agency quoted the ruling party's Rodong Sinmun newspaper as saying that North Korea had "clarified its resolute stand that it would take countermeasures including nuclear test to protect the sovereignty and dignity of the" country.

The Institute for Science and International Security think tank said Saturday that satellite imagery from the previous day showed ongoing activities at North Korea's nuclear test site, including movement of possible vehicles, trucks and containers.

On Thursday, South Korean Defense Minister Kim Kwan-jin said that North Korea was making final preparations to conduct its fourth nuclear test.