SEOUL, South Korea — North Korea said on Tuesday that it had successfully conducted its first test of an intercontinental ballistic missile, claiming a milestone in its efforts to build nuclear weapons capable of hitting the mainland United States.
The announcement came hours after a launch that the United States military said had sent the missile aloft for 37 minutes. That duration, analysts said, suggested a significant improvement in the range of the North’s missiles, and it might allow one to travel as far as 4,000 miles and hit Alaska.
In an initial statement, the United States Pacific Command described the weapon as an intermediate-range missile rather than an intercontinental ballistic missile. But South Korean and Japanese officials said they were studying the data to determine if it was an ICBM.
The missile departed the Banghyon airfield in the northwestern town of Kusong and flew 578 miles before landing in the sea between North Korea and Japan, the South Korean military said in a statement.