N. Korea has yet to master re-entry technology for ICBM: Defense minister

North Korea has yet to master ballistic missile technology that can allow a warhead to re-enter the Earth's atmosphere after flying through space, Seoul's top defense official said Friday, refuting Pyongyang's claims that it can build an inter-continental ballistic missile (ICBM).

On Tuesday, Pyongyang claimed it has acquired the re-entry technology with the country also releasing photos of a ground-based simulation and what is described as the tested re-entry vehicle that had a mushroom shape.

A re-entry vehicle protects a ballistic missile's warhead through the course of its flight, including the re-entry stage.

Without proper protection, a missile's warhead will burn up from the heat and pressure.

The North said its test subjected the re-entry vehicle to 1,500 to 1,600 degrees Celsius of intense heat.

Defense Minister Han Min-koo said during his appearance on a local broadcast news program that existing re-entry vehicles can withstand upwards to 7,000 degrees Celsius of heat in addition to other types of ablation effects like extreme pressure and vibrations. 

"I don't think North Korea has gained the re-entry technology in this test and many experts also share that point," he said. 

On its efforts to make small nuclear weapons that can be mounted onto ballistic missiles, North Korea may have made significant strides, although the country's claim to own a real nuclear warhead is dubious, Han noted.

"North Korea has steadily conducted nuclear tests, and now it has become a realistic threat," the defense chief said, adding that the South Korean military is maintaining its readiness posture to deal with any threats. 

North Korea has come very far in diversifying and making its missile arsenal more sophisticated, he said, referring to the country's programs for the submarine launched ballistic missile and the KN-08 intercontinental missile. 

North Korea is technically ready to conduct an additional nuclear test at any time, he also noted, saying that another nuclear test can take place at a moment's notice.

"We should squarely face the fact that North Korea's nuclear weapons are aimed at South Korea, not other countries," Han pointed out, calling for public support for denuclearizing of the North. (Yonhap)