SEOUL: North Korea's Kim Jong Un ordered the military to intensify drills to deter and respond to a "real war" if necessary, state media said on Friday, after the leader oversaw a fire assault drill that it said proved the country's capabilities.

North Korea fired a short-range ballistic missile off its west coast on Thursday, South Korea's military said, adding it was analysing possibilities the North may have launched multiple missiles simultaneously from the same area.

Photos released by the North's KCNA news agency showed at least six missiles being fired at the same time.

KCNA said a unit trained for "strike missions" fired a "powerful volley at the targeted waters" and demonstrated its capability to "counter an actual war."

"(Kim) stressed that the fire assault sub-units should be strictly prepared for the greatest perfection in carrying out the two strategic missions, that is, first to deter war and second to take the initiative in war, by steadily intensifying various simulated drills for real war ...," KCNA said.

Kim was accompanied by his young daughter who has appeared recently in a series of major events.

The latest missile launches came as the United States and South Korea were set to kick off large-scale military exercises known as the Freedom Shield drills next week. North Korea has long bristled at the allies' drills as a rehearsal for invasion.

North Korean leader Kim's sister, Kim Yo Jong, said earlier this week any move to shoot down one of its test missiles would be considered a declaration of war and blamed a joint military exercise between the United States and South Korea for growing tensions.

The U.S. Indo-Pacific Command said the latest launch posed no threat to the United States or its allies but Pyongyang's weapons of mass destruction and ballistic missile programs have a destabilising effect on the region.

The United States will hold an informal meeting of United Nations Security Council members next week on human rights abuses in North Korea, a move likely to anger Pyongyang and spur opposition from China and Russia.