By Ju-min Park and James Pearson
SEOUL, May 11 (Reuters) - North Korea made a key step in its nuclear weapons program by test-launching a ballistic missile from a submarine, but remains years away from developing a missile system or submarine which could threaten its sworn enemy the United States, experts said.
South Korea on Monday called the test "very serious and concerning" and urged Pyongyang to immediately stop developing submarine-launched ballistic missiles (SLBMs), which it said hindered regional security.
Isolated North Korea, already slapped with UN sanctions for its missile and nuclear tests, is widely believed to be trying to develop a nuclear device small enough to be mounted on a ballistic missile, but it is not clear whether it has done so - a crucial step to make its nuclear missile threat credible.
And while some North Korean submarines are technically capable of coming within range of the U.S. mainland, they cannot necessarily carry a missile, although the North's missile-equipped submarines could reach Japanese waters.
"They need to build a new, bigger submarine," said Yang Uk, a senior research fellow at the Korea Defense and Security Forum and a policy adviser to the South Korean navy.
In this April 9, 2014, file photo made from video, North Korean leader Kim Jong Un holds up a parliament membership certificate during the Supreme People's Assembly in Pyongyang, North Korea. (AP Photo/KRT via AP Video, File)
North Korea is technically still at war with the South after their 1950-53 conflict ended in a truce, not a peace treaty, and regularly threatens the United States, the South's biggest ally, with destruction.
Both the United States and Japan reserve rights to conduct pre-emptive strikes on North Korean missile sites if a nuclear attack is viewed as imminent. Launching missiles from submarines could enable Pyongyang to hide them.
"While North Korea's submarines are not especially effective, the challenge of finding even a small number of specific submarines armed with missiles would be quite a challenge," said Jeffrey Lewis of the California-based Monterey Institute of International Studies.
Like much of North Korea's arsenal, its fleet of around 70 submarines is based mainly on aging, Soviet-era technology.
North Korea had been expected to be working on an SLBM, but the speed with which it conducted an evidently successful test launch caught many observers by surprise.
A North Korea soldier stands guard on the banks of the Yalu River which separates the North Korean town of Sinuiju from the Chinese border town of Dandong on the second anniversary of the death of former leader Kim Jong-Il, December 17, 2013. (MARK RALSTON/AFP/Getty Images)
A South Korean defense ministry official who declined to be identified said photographs released on Saturday by the North showing a missile launched from the sea appeared to be authentic.
The official also said that the North could be capable of building a fully-operational submarine equipped with ballistic missiles within two or three years - a shorter time frame than many analysts say is needed.
Before it can head towards its target on an arched trajectory, an SLBM must be ejected and travel to the sea's surface, which is what North Korea appears to have done. The missile traveled only about 150 meters, the South Korean official said.
Yang said the system was likely years away from deployment because North Korean submarines were not well enough equipped to manage the radar and tracking systems required to guide a missile to its target.
Lewis said the missile that North Korea tested probably has a range of roughly 2,400 km (1,500 miles), which would require a submarine to be at sea for 60-90 days.
"That means a journey to bring the U.S. in range would be pretty daring."
Our 2024 Coverage Needs You
It's Another Trump-Biden Showdown — And We Need Your Help
The Future Of Democracy Is At Stake
Our 2024 Coverage Needs You
Your Loyalty Means The World To Us
As Americans head to the polls in 2024, the very future of our country is at stake. At HuffPost, we believe that a free press is critical to creating well-informed voters. That's why our journalism is free for everyone, even though other newsrooms retreat behind expensive paywalls.
Our journalists will continue to cover the twists and turns during this historic presidential election. With your help, we'll bring you hard-hitting investigations, well-researched analysis and timely takes you can't find elsewhere. Reporting in this current political climate is a responsibility we do not take lightly, and we thank you for your support.
Contribute as little as $2 to keep our news free for all.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
The 2024 election is heating up, and women's rights, health care, voting rights, and the very future of democracy are all at stake. Donald Trump will face Joe Biden in the most consequential vote of our time. And HuffPost will be there, covering every twist and turn. America's future hangs in the balance. Would you consider contributing to support our journalism and keep it free for all during this critical season?
HuffPost believes news should be accessible to everyone, regardless of their ability to pay for it. We rely on readers like you to help fund our work. Any contribution you can make — even as little as $2 — goes directly toward supporting the impactful journalism that we will continue to produce this year. Thank you for being part of our story.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
It's official: Donald Trump will face Joe Biden this fall in the presidential election. As we face the most consequential presidential election of our time, HuffPost is committed to bringing you up-to-date, accurate news about the 2024 race. While other outlets have retreated behind paywalls, you can trust our news will stay free.
But we can't do it without your help. Reader funding is one of the key ways we support our newsroom. Would you consider making a donation to help fund our news during this critical time? Your contributions are vital to supporting a free press.
Contribute as little as $2 to keep our journalism free and accessible to all.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
As Americans head to the polls in 2024, the very future of our country is at stake. At HuffPost, we believe that a free press is critical to creating well-informed voters. That's why our journalism is free for everyone, even though other newsrooms retreat behind expensive paywalls.
Our journalists will continue to cover the twists and turns during this historic presidential election. With your help, we'll bring you hard-hitting investigations, well-researched analysis and timely takes you can't find elsewhere. Reporting in this current political climate is a responsibility we do not take lightly, and we thank you for your support.
Contribute as little as $2 to keep our news free for all.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
Dear HuffPost Reader
Thank you for your past contribution to HuffPost. We are sincerely grateful for readers like you who help us ensure that we can keep our journalism free for everyone.
The stakes are high this year, and our 2024 coverage could use continued support. Would you consider becoming a regular HuffPost contributor?
Dear HuffPost Reader
Thank you for your past contribution to HuffPost. We are sincerely grateful for readers like you who help us ensure that we can keep our journalism free for everyone.
The stakes are high this year, and our 2024 coverage could use continued support. If circumstances have changed since you last contributed, we hope you'll consider contributing to HuffPost once more.
Support HuffPostAlready contributed? Log in to hide these messages.