SEOUL, South Korea — North Korea on Wednesday fired a ballistic missile from a submarine into the sea in an apparent protest against the start of annual South Korea-U.S. military drills, Seoul's military said.
The missile fired from a submarine off the eastern coastal town of Sinpo flew about 310 miles, the longest flight of a North Korean submarine-launched missile, Seoul's Joint Chiefs of Staff said in a statement. U.S. Strategic Command said it had tracked the North Korean submarine launch of the presumed KN-11 missile over and into the Sea of Japan.
North Korea fired two other missiles from submarines earlier this year but they were believed to have exploded in midair after flying several or 18 miles, according to South Korean defense officials.
The North's acquiring the ability to launch missiles from submarines would be an alarming development because missiles fired from submerged vessels are harder to detect in advance. The U.S. Strategic Command statement said the North Korean launch did not pose a threat to North America but that the U.S. military "remains vigilant in the face of North Korean provocations."
North Korea's missile and nuclear programs are a source of regional security concerns. Outside experts say the North doesn't yet have a reliable long-range nuclear missile capable of reaching the continental U.S. but they acknowledge the North has been making steady progress on its weapons programs and could one day acquire such a weapon.
Some civilian experts said they believe the North already has the technology to put warheads on shorter-range missiles that can strike South Korea and Japan.
Wednesday's launch comes two days after the U.S. and South Korea began their 12-day Ulchi Freedom Guardian exercises, prompting North Korean threats of retaliation.
The South Korean military statement said it considers the North Korean missile launch as an "armed protest" against the military drills and a challenge to peace on the Korean Peninsula. It also noted that the launch violated U.N. Security Council resolutions that ban any ballistic missile activities by North Korea.
The launch also comes at a time of intensified animosities between the rival Koreas over the defection of a senior North Korean diplomat in London and a U.S. plan to install a sophisticated missile defense system in South Korea.
About 28,500 U.S. troops are based in South Korea to help deter potential aggression from North Korea, a legacy of the 1950-53 Korean War that ended with an armistice, not a peace treaty.
North Korea usually responds to the regular South Korea-U.S. military drills with weapons tests and fiery warlike rhetoric.