North Korea conducted what is thought to be its largest intercontinental ballistic missile (ICBM) test ever today, militaries in South Korea and Japan said, marking a dramatic end to a self-imposed moratorium on long-range testing.

It would be the first full-capability launch of the nuclear-armed state's largest missiles since 2017, and represents a major step in the North's development of weapons that might be able to deliver nuclear warheads anywhere in the United States.

The North's return to...