SEOUL, South Korea (AFP) — North Korea’s Kim Jong Un oversaw drills that simulated nuclear counterstrikes against Seoul and Washington, state media said Friday, a day after South Korea’s military flagged missile tests by Pyongyang that violated sanctions.

Seoul’s military said Thursday’s tests, which involved “various types” of short-range ballistic missiles, could be linked to the nuclear-armed North’s weapons exports to Moscow.

The drills involved a 600-millimeter multilayer rocket system and a tactical ballistic missile, Pyongyang’s official Korean Central News Agency (KCNA) said.

Detailed trainings on “procedures and processes for rapidly switching over to the nuclear counterattack posture” took place, according to KCNA.

“The goal of the drill was achieved and the reliability of the command and mobilization system capable of quickly reacting to any nuclear crisis was verified,” the news agency added.

Kim earlier this week inspected shell manufacturing at munitions factories, with state media claiming the country’s shell output had increased dramatically in recent months.

South Korea’s military said in early March that the North fired “multiple unidentified ballistic missiles,” the same day Seoul and Washington began a major annual joint military drill known as Freedom Shield.