(CNN)North Korea has fired what is believed to be a submarine-launched ballistic missile off the east coast of the Korean peninsula, the South Korean Joint Chiefs of Staff said Saturday.
The missile was fired at 6:30 p.m. local time (5:30 a.m. ET), South Korean officials said, and appears to have flown for about 30 km (about 19 miles) -- well short of the 300 km (roughly 186 miles) that would be considered a successful test. One U.S. official said Saturday the launch "was provocative but not a threat to the U.S. and the missile was fired away from South Korea and Japan." But another U.S. official noted that after previous launch attempts by Pyongyang that didn't appear to be successful, this one seems to have gone much better. "North Korea's sub launch capability has gone from a joke to something very serious," this official said. "The U.S. is watching this very closely." Launching a missile from a submarine has always been a military priority for North Korea, CNN's Barbara Starr reports, and if this test was successful, it would be a military victory for Pyongyang. But such a launch is in violation of U.N. Security Council resolutions, the U.S. State Department said. "We have seen the reports that North Korea launched what appeared to be a ballistic missile from a submarine in the Sea of Japan," State Department spokesman John Kirby said in a statement. "Launches using ballistic missile technology are a clear violation of multiple U.N. Security Council resolutions." "We call on North Korea to refrain from actions that further destabilize the region and focus instead on taking concrete steps toward fulfilling its commitments and international obligations. "The United States remains steadfast in its commitments to the defense of its allies. We will continue to coordinate closely with the ROK, Japan, and other allies and partners," Kirby added. Previous launch a failure Saturday's launch comes about a week after another attempt, which was apparently unsuccessful. A U.S. defense official said April 14 that U.S. Strategic Command systems detected and tracked an attempted North Korean missile launch, but there was "no evidence the missile reached flight," a U.S. official told Starr. Tensions have ratcheted up on the divided Korean peninsula this year as Pyongyang has made a series of assertions about developments in its military capability. South Korea's military did not specify what sort of missile was part of the April 14 test, but South Korean media reports said it involved an intermediate-range Musudan missile. Pyongyang carried out its fourth nuclear test in January. It said it succeeded in miniaturizing nuclear warheads to fit on medium-range ballistic missiles -- which U.S. intelligence analysts say is probably true. South Korean military on state of high alert Ballistic missiles are missiles fired in an arc toward their targets. CNN's Paula Hancocks said it was not yet known whether the latest North Korean test was a success. But she said the ability to launch ballistic missiles from submarines makes the possible launch points far more difficult to detect. The South Korean military remained on a state of high alert following the test, Hancocks said.
CNN's Kevin Liptak, Barbara Starr, Jim Sciutto and journalist Kim Jung-Eun contributed to this report.