North Korea leader Kim Jong Un supervised a successful test of a new engine for an Intercontinental Ballistic Missile (ICBM), state media said on Saturday, in their latest report of advances in an arms programme that has attracted U.N. sanctions.

North Korea has made substantial progress in its efforts to complete its development of hydrogen bombs. The North’s missile and nuclear technology is at a considerable level,” Wu Dawei was quoted as saying by Japanese media.

On Apr. 5, China’s Ministry of Commerce officially announced that it was banning North Korean imports and exports of coal, iron and jet fuel in accordance with UN Security Council Resolution No. 2270. In regard to items connected to North Koreans’ livelihood – which are classified as exceptions to the resolution – China has decided to review applications submitted by its customs authorities

Some analysts think young leader Kim Jong-un’s belligerent stance is linked to a major ruling party congress next month meant to further cement his grip on power. The outside pressure and anger caused by bombastic threats and repeated nuclear-related tests, the argument goes, is meant to rally the North Korean people around Kim as he stands up to powerful enemies trying to crush the North.

“With all the missiles they’re building, the ranges are getting longer and they’re going to be able to throw more stuff further,” said Jeffrey Lewis, director of the East Asia program at the James Martin Center for Nonproliferation Studies in Monterey, Calif.

Previous estimates of North Korea’s firepower had it just able to reach the continental United States, but if it had successfully manufactured an 80-ton booster — as the Treasury Department recently claimed in sanctions against Pyongyang — it would put the U.S. mainland within relatively easy reach, analysts said.

Image Source: koreajoongangdaily.joins.com