A previous 2001 accord with Washington had barred South Korea from deploying ballistic missiles with a range of more than 300 kilometers (186 miles) and a payload of more than 500 kilograms (1,100 pounds) because of concerns about a regional arms race.
The Korean Peninsula remains officially at war because the 1950-53 Korean War ended with an armistice, not a peace treaty. The U.S. stations about 28,500 troops in South Korea as deterrence against possible aggression from North Korea.
Associated Press writers Eric Talmadge in Tokyo and Matthew Pennington in Washington contributed to this report.
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