The missile was launched "within the last 90 minutes," Colonel Rob Manning, a Pentagon spokesman, said around 2200 GMT Monday (6:30 am Tuesday in Pyongyang).
"We assess North Korea conducted a missile launch within the last 90 minutes. We can confirm that the missile launched by North Korea flew over Japan," Manning added, cautioning that the United States was still assessing the launch.
However, North American Aerospace Defense Command (NORAD) "determined the missile launch from North Korea did not pose a threat to North America," Manning said.
South Korea's Joint Chiefs of Staff said in a statement that the missile was launched around 2057 GMT Monday from Sunan, near Pyongyang, and traveled east "and over Japan."
It travelled around 1,700 miles (2,700 kilometers) at a maximum altitude of around 350 miles, it said, adding that South Korea and the US were "closely analysing for more details."
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