North Korea's Kim leads 'nuclear counterattack' simulation drill

North Korean leader Kim Jong Un led two days of military drills "simulating a nuclear counterattack", including the launch of a ballistic missile, state media reported Monday.

Kim expressed satisfaction over the weekend drills, which were held to "let relevant units get familiar with the procedures and processes for implementing their tactical nuclear attack missions", said the report by the official Korean Central News Agency (KCNA).

The drills were the fourth show of force from Pyongyang in a week and came during Freedom Shield, the biggest US-South Korea military exercise in five years.

North Korea views all such exercises as rehearsals for invasion and has repeatedly warned it would take "overwhelming" action in response.

The weekend drills in North Korea were divided into exercises simulating the shift to a nuclear counterattack posture and a drill for "launching a tactical ballistic missile tipped with a mock nuclear warhead", KCNA said.

South Korea's Joint Chiefs of Staff said Sunday that the short-range ballistic missile flew 800 kilometres (500 miles) before landing in the East Sea, also known as the Sea of Japan.

They branded it a "serious provocation" that violated United Nations sanctions.

Kim said the weekend drills had filled the North Korean military units "with great confidence", according to KCNA.

He also noted that North Korea "cannot actually deter a war with the mere fact that it is a nuclear weapons state", and that it could only reach its goals "when the nuclear force is... actually capable of mounting an attack on the enemy."

Yang Uk, a researcher at the Asan Institute for Policy Studies, said the weekend drills demonstrated that North Korea's nuclear posture was becoming "a...