Kim Jong-un has said North Korea will soon detonate another nuclear warhead and test launch ballistic missiles capable of carrying them, according to the official KCNA news agency.



Kim made the comments as he supervised a successful simulated test of atmospheric re-entry of a ballistic missile that measured the “thermodynamic structural stability of newly developed heat-resisting materials”, KCNA said.

“Declaring that a nuclear warhead explosion test and a test-fire of several kinds of ballistic rockets able to carry nuclear warheads will be conducted in a short time to further enhance the reliance of nuclear attack capability, he [Kim] instructed the relevant section to make prearrangement for them to the last detail,” the agency said.

The report comes amid heightened tensions on the Korean peninsula as South Korean and US troops stage annual military exercises that Seoul has described as the largest ever. The North has issued belligerent statements almost daily after coming under new United Nations sanctions.

The United Nations security council imposed a new resolution to tighten sanctions against the North after a nuclear test in January and the launch of a long-range rocket in February.

US and South Korean experts have said the general consensus was that North Korea had not yet successfully miniaturised a nuclear warhead to be mounted on an intercontinental ballistic missile, but Kim has insisted that his country has indeed done so.

Experts have also said there have been no tests of the re-entry technology needed to bring a nuclear warhead back into the atmosphere to strike a target – and following the regime’s established pattern of responses, Kim on Tuesday that this technology had been proven in the laboratory. South Korea said there was nothing to prove the “one-sided claim”.



The North, which has conducted four nuclear tests, also claimed in January to have successfully tested a hydrogen bomb but most experts said the blast was too small to back up the assertion.



The North says the satellites it has launched into orbit are functioning successfully, although that has never been independently verified.

With Reuters and Agence France-Presse