The launch "is in outright violation of (North Korea's) international obligations as set out in several UN Security Council resolutions," the EU's foreign service said in a statement.
It urged Pyongyang "to refrain from any further provocative action that could increase regional and global tensions".
EU foreign ministers, at a meeting in July, had condemned North Korea's missile launches in similar terms.
EU diplomatic chief Federica Mogherini will take up the issue in the coming days with the foreign ministers of South Korea "and other international partners," the statement said.
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Tonight's launch entailed the firing of what appeared to be another intercontinental ballistic missile, according to the Pentagon.
Japanese Prime Minister Shinzo Abe said the missile may have landed within Japan's maritime exclusive economic zone.
The launch came a day after North Korea celebrated what it calls "Victory Day" -- the anniversary of the end of the 1950-53 Korean War. Pyongyang regularly times its missile tests to coincide with symbolic dates.