North Korea's Kim warns Washington as biggest ICBM launched

PYONGYANG - North Korean leader Kim Jong Un has vowed to accelerate his country's nuclear build-up and warned Washington against making a "wrong decision" after overseeing the launch of the country's most powerful ballistic missile, state media said.

Monday's test launch of the solid-fuel Hwasong-18 came a day after the nuclear-powered submarine USS Missouri made port in Busan and followed a US-South Korea warning that a nuclear attack by Pyongyang would mean "the end of the Kim regime".

The two allies along with Japan on Tuesday activated a system to share real-time data on North Korean launches, part of their tightening security cooperation in response to Pyongyang's growing nuclear threats.

Kim said the launch of the missile capable of reaching US shores was "a clear signal to hostile forces" and showed the country's options should Washington make "a wrong decision against it", the Korean Central News Agency said.

"A drill of launching (the) ICBM Hwasongpho-18 was staged as an important military action to clearly show the DPRK's nuclear strategic forces' overwhelming counteraction will and matchless strength to the enemies," KCNA said of the Monday launch.

The North Korean leader, who pictures showed in attendance with his young daughter, clad in a pink fur jacket, also "set forth some important new tasks for the development of the DPRK's nuclear strategic forces," KCNA added.

The Hwasong-18, the largest in North Korea's arsenal, flew just over 1,000 kilometres and reached a maximum altitude of around 6,000 kilometres, it said, and demonstrated "the combat capability of ICBM unit".

South Korea's military said Monday that the ICBM fired used solid fuel, which makes missiles easier to transport and faster to fire than liquid-fuelled versions.

The launch marked the third time the North had tested a solid-fuel ICBM, after launches in April and July, which analysts said signalled consistent efforts to improve the technology.

Japan's defence ministry said the Hwasong-18 had a potential range of more than 15,000 kilometres, which would cover all of the United States.