New Delhi: North Korean leader Kim Jong Un supervised two days of drills "simulating a nuclear retaliation," including the launch of a ballistic missile carrying a mock nuclear warhead, the news agency AFP reported citing the state news agency KCNA, while South Korea and the United States continued their own military exercises.


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", KCNA reported on Monday.


North Korea launched four rounds of weapons tests since the US and South Korean militaries began joint military drills last week- 11 days of military exercises called Freedom Shield, their largest 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 nuclear force of the DPRK will strongly deter, control and manage the enemy’s reckless moves and provocations with its high war readiness, and carry out its important mission without hesitation in case of any unwanted situation,” KCNA quoted Kim as saying, using the acronym of his country’s official name, the Democratic People’s Republic of Korea.


Pyongyang on Sunday morning fired a short-range ballistic missile toward the sea off the east coast of the Korean Peninsula, AFP reported.


Saturday and Sunday's drills 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.


"The missile was tipped with a test warhead simulating a nuclear warhead," it added later, without giving further details.


On Thursday, Pyongyang test-fired its largest and most powerful intercontinental ballistic missile, the Hwasong-17, its second ICBM test this year, according to AFP.


The UN Security Council is expected to hold an emergency meeting today over the ICBM launch at the request of the United States and Japan, Yonhap news agency reported.


Seoul and Washington have ramped up defence cooperation in the face of growing military and nuclear threats from the North, which has conducted a series of banned weapons tests in recent months.


North Korea declared itself last year an "irreversible" nuclear power and Kim recently called for an exponential increase in weapons production, including tactical nuclear weapons.


Kim also ordered the North Korean military this month to intensify drills to prepare for a "real war".


(With agency inputs)