North Korea is calling its underwater ballistic missile test on Saturday a success, but South Korean officials disagree.
North Korean media says leader Kim Jong-un ordered and guided the submarine-launched missile, adding to the navy's arsenal.
But South Korea says this type of missile can typically travel at least 186 miles and the test only flew a little more than 18 miles.
This test comes during ongoing U.S.-South Korea military exercises and North Korean nuclear tests over the past few months.
The possibility of another nuclear test has put South Korea's military on alert.
And a U.S. State Department spokesman says, "Launches using ballistic missile technology are a clear violation of multiple U.N. Security Council resolutions."