North Korea fired what appeared to be a new model ballistic missile on Thursday, South Korea said, triggering a scare in northern Japan where Hokkaido residents were told to take cover, though there turned out to be no danger.

“The test proved … the new intercontinental ballistic missile’s military efficiency as a strategic attack capability,” news agency KCNA said, adding it will dramatically improve the country’s strategic deterrence and nuclear counterattack readiness.

Leader Kim Jong-un guided the test, KCNA said.

Developing a solid-fuel ICBM has long been seen as a key goal for North Korea, as it could help the North deploy its missiles faster in the event of a war.

The latest launch came days after North Korean leader Kim called for strengthening war deterrence in a “more practical and offensive” manner to counter what North Korea called moves of aggression by the US.

North Korea has criticised recent US-South Korean joint military exercises as escalating tensions and has stepped weapons tests in recent months.