North Korea said Monday its test a day earlier involved a new Hwaseong-12 missile – capable of carrying a “large-size heavy nuclear warhead”.

The claim was reported by Pyongyang’s official KCNA news agency as the United Nations Security Council is expected to soon condemn the launch as a violation of multiple resolutions.

Having overseen the test, leader Kim Jong-un warned the U.S mainland and Pacific bases are in North Korea’s “sighting range”.

The KCNA dispatch also asserted the test was aimed at “verifying the tactical and technological specifications of the newly developed ballistic rocket capable of carrying a large-size heavy nuclear warhead”.

Kim proclaimed his nation’s development of intercontinental ballistic missile technology earlier this year.

But South Korea’s Joint Chiefs of Staff (JCS) expressed doubts whether the North has mastered the necessary atmospheric re-entry technology.

According to local news agency Yonhap, a JCS official told reporters, “We believe chances (of it) are low".

The official did verify Pyongyang’s claim that its latest test achieved a height of 2,111.5 kilometers and traveled 787 kilometers before landing in open water.