North Korea’s successful missile test-launch signals major advances in developing an intercontinental ballistic missile, such as mastery of re-entry technology and better engine performance key to targeting the United States, experts say.

The isolated country has been developing a long-range missile capable of striking the mainland United States mounted with a nuclear warhead. That would require a flight of 8,000 km (4,800 miles) or more and technology to ensure a warhead’s stable re-entry into the atmosphere.

The North’s official KCNA news agency said the new strategic ballistic missile named Hwasong-12, fired on Sunday at the highest angle to avoid affecting neighboring countries’ security, flew 787 km (489 miles) on a trajectory reaching an altitude of 2,111.5 km (1,312 miles). […]