State-run media says North Korean leader Kim Jong Un attended the launch. The missile was fired from an international airport in Sunan, a suburb of Pyongyang.
Japanese officials believe it fell into the sea about 150 kilometers from the northern prefecture of Hokkaido. That is inside Japan's exclusive economic zone.
The report says the missile reached an altitude of more than 6,200 kilometers. It says it flew for about 67 minutes over a distance of about 1,100 kilometers, and it accurately hit its target in the sea.
This is the country's first full-scale launch of an ICBM since November 2017. The following year, North Korea said it would stop testing this type of weapon and also suspend its nuclear tests.