North Korea has built a new test stand on its eastern coast to research and develop ballistic missiles that can be launched from submarines, a U.S. think tank said Tuesday, citing commercial satellite imagery.

The assessment from the website 38 North, run by the U.S.-Korea Institute at the Johns Hopkins School of Advanced International Studies, is in line with South Korea's intelligence that the North is believed to be developing a submarine-launched ballistic missile (SLBM).

"A review of commercial satellite imagery ... has identified a new test stand at the North's Sinpo South Shipyard, probably intended to explore the possibility of launching ballistic missiles from submarines or of a shipboard vertical launch ballistic missile capability," said arms expert Joseph S. Bermudez Jr. in a report on the website.

"The new installation is the right size and design to be used for the research, development, and testing of the process of ejecting a missile out of a launch tube as well as evaluating its compatibility with submarines and surface combatants as well as the missiles themselves," he said.

Construction of the new stand was first spotted in the fall of last year and is believed to have been completed by April, the expert said. The stand consists of a 35-by-30-meter concrete pad with an approximately 12-meter-high test stand, he said.

Last month, South Korea's Joint Chiefs of Staff said in a report to a lawmaker that there is an indication that the North is developing an SLBM. A military source also said intelligence agencies spotted signs that the North has developed a ballistic missile launch tube for submarine use.

Bermudez said, however, that the potential SLBM threats from the North should not be exaggerated.

"If the North decides to pursue such a capability, it is likely to take years to design, develop, manufacture, and deploy an operational submarine-launched ballistic missile force," he said.

North Korea is believed to have sophisticated ballistic missile technologies after carrying out a series of long-range rocket tests for decades. In the latest test, in late 2012, the communist nation put a satellite into orbit in what was condemned as a test of ballistic missile technology.

Such rocket technologies, when combined successfully with the North's nuclear program, would mean that the North would be capable of building nuclear-tipped intercontinental ballistic missiles capable of reaching the U.S. mainland.

On Tuesday, State Department spokeswoman Jen Psaki urged the North to abandon its ballistic missile program, calling it and other related activities "clear violations of multiple U.N.

Security Council resolutions." The activities have been condemned by the international community, she added.

"We continue to urge North Korea to comply with its U.N.

Security Council obligations," she said. "North Korea must suspend all activities related to its ballistic missile program, stop conducting any launches using ballistic missile technology and abandon its ballistic missile program in a complete, verifiable and irreversible manner." (Yonhap)