North Korean leader Kim Jong Un called on his navy to accelerate its nuclear armament as the country’s newest warship conducted a series of weapons tests, state media reported.

South Korea has condemned Pyongyang’s first public admission that its troops fought alongside Russian forces against Ukraine, calling the move a violation of international law.

U.S. and South Korean forces sharpened their nuclear response plans this month with a tabletop exercise and Seoul’s first-ever nuclear weapons effects training, as tensions with North Korea persist.

A South Korean soldier accidentally discharged a machine gun last week while inspecting the weapon at a guard post inside the Demilitarized Zone, according to the Ministry of National Defense.

The official voice of North Korea’s authoritarian regime on Friday denounced the recent appearance of Air Force long-range bombers in Japan as a “vicious change” and a “threat to regional security.”

The South Korean military resumed artillery practice this week at a firing range in Paju, the first such drill at the range near the northern border since the two Koreas suspended a deconfliction agreement last year.