SEOUL, South Korea - North Korean leader Kim Jong Un called for a strengthened nuclear deterrent and warned he would have no hesitation in "annihilating" the rival South, while touring major weapons factories, state media reported Wednesday.

Labeling South Korea the "principal enemy", he said Pyongyang's priority should be to "bolster up the military capabilities for self-defence and the nuclear war deterrent first of all", according to the official Korean Central News Agency.

Relations between the two Koreas are at one of their lowest points in decades, after Kim enshrined the country's status as a nuclear power into the constitution and test-fired several advanced intercontinental ballistic missiles.

Kim said that while the North -- formally known as the Democratic People's Republic of Korea (DPRK) -- would not "unilaterally" trigger a confrontation, it had "no intention of avoiding a war as well", according to KCNA.

"If the ROK dares attempt to use armed forces against the DPRK or threaten its sovereignty and security and such opportunity comes, we will have no hesitation in annihilating the ROK by mobilizing all means and forces in our hands," KCNA reported, using an acronym for the southern Republic of Korea.

Kim, accompanied by senior party and military officials, conducted his tour of multiple munitions factories on Monday and Tuesday, KCNA said, describing the visits as encouragement for weapons workers "in the struggle for attaining the huge production goal for the new year".

The United States and dozens of allies, including South Korea and Japan, accuse North Korea of violating multiple international sanctions by transferring missiles to Russia to help bolster its military invasion of Ukraine.