SEOUL—North Korea said it successfully test-launched an intercontinental ballistic missile, claiming a major advance in its attempts to threaten the U.S. with a nuclear weapon.

The announcement was made on North Korean state television on Tuesday afternoon—in the early hours of Independence Day in the U.S.

The missile, identified as the Hwasong-14, reached an altitude of 2,802 kilometers (1,737 miles) and flew 933 kilometers (580 miles), according to North Korean state television, before splashing down between Korea and Japan. The numbers are in line with analyses from U.S., South Korean and Japanese military authorities.

North Korean leader Kim Jong Un said earlier this year that the country was close to test-launching an ICBM. U.S. President Donald Trump said on Twitter a day later: “It won’t happen!”

A North Korean ICBM could change the strategic calculus between Washington and Pyongyang, as Mr. Kim’s regime continues to defy United Nations sanctions and warnings from its neighbors to curb its nuclear and weapons programs.