North Korea conducted a launch of a Pukkuksong-1 submarine-launched ballistic missile (SLBM) off its east coast late Saturday morning, South Korea’s Yonhap News Agency reported.

The North launched a single Pukkuksong-1 SLBM (also known as the KN-11 by the United States and South Korea) from a Sinpo-class (a.k.a. Gorae-class) submarine in the waters of the Sea of Japan (known in Korea as the East Sea) near Sinpo, South Hamgyong Province, at around 11:30 a.m. Saturday.

South Korea’s Joint Chiefs of Staff reported that the missile flew about 30 kilometers before exploding and breaking into two or three pieces. The JCS assessed that though the missile successfully ejected from the submarine, the flight portion of the test was a failure.

North Korea is prohibited from developing and launching ballistic missiles under multiple UN Security Council resolutions, mainly due to its ongoing nuclear weapons testing and long-range rocket launching programs.

“I do believe that North Korea will continue efforts to miniaturize its nuclear weapons and load them on SLBMs,” Moon Keun-sik, the director at the Korea Defense and Security Forum, told NK News following a previous SLBM launch in April.

“But SLBM launches need multiple test launches to refine, both on land and at sea, so they will continue launches until they successfully launch the SLBM loaded with a warhead,” he added.

North Korea conducted a failed SLBM launch in late November 2015 and another, possibly successful, launch in May of the same year.”

Moon told NK News on Saturday that the launch could be a response to the decision of the U.S. and South Korea to deploy a Terminal High-Altitude Air Defense (THAAD) battery on the Korean Peninsula. He also noted that it may be difficult to defend against such a missile.

“As we do not know where the SLBM would be launched from, it is very hard to detect its launch and is the hardest type of weapon to defend SK with THAAD,” said Moon.

“This North Korean launch was meant to ridicule South Korea for the recent decision made to deploy THAAD system”

Dr. Andray Abrahamian, North Korea researcher at Macquarie University, said this test may also be a response to recent sanctions.

“Sometimes these tests serve an important technical purpose and sometimes sanctions have a practical aim,” Abrahamian told NK News. “Last week we saw a sanctions action that was largely symbolic and this missile test is too, I suspect.”

“Both sides are signaling to one another that they won’t be backing down anytime soon,” said Abrahamian.

On Wednesday, the U.S. Treasury Department’s Office of Foreign Assets Control (OFAC) expanded sanctions against North Korea to target officials – including Kim Jong Un – and entities associated to the North’s human rights violations.

Following the previous launch of such an SLBM in April, Pyongyang’s state media quoted a military official on the significance of the missile.

“As one of the military officials who participated in the recent SLBM launch, our ballistics – following our own underwater launch mechanism – have reached a technical level sufficient to conduct attacks from underwater at any given time,” North Korean strategy submarine officer Lee Myung Sung wrote on the state-owned bulletin DPRK Today.

“Our enemies’ claims on the need for (the SLBM to have) a ‘minimum range of 300 kilometers’ is not even worth considering for us.”

On the day of the April SLBM launch, the South Korean Joint Chief of Staffs (JCS) said the North Korean projectile traveled around 30 kilometers, only 10 percent of the missile’s estimated range of 300 kilometers, the Korea Herald reported.

Land-based testing of the Pukkusong-1 SLBM began as early as 2013, when the test stand at Sinpo was built, and the first confirmed submerged test launch was conducted in May 2015.

The Pukkusong-1 SLBM is believed to be based on the visually-similar Soviet-designed R-27 Zyb (NATO reporting name SS-N-6) SLBM.

Featured image: Pukkuksong-1 test launch, Korean Central News Agency