The United States expressed concern Tuesday over North Korea's recent failed test of a submarine-launched ballistic missile and urged Pyongyang to refrain from violating U.N. Security Council resolutions.

Yonhap News Agency reported exclusively that the North fired a KN-11 missile from a submarine in the East Sea on Saturday, but the missile failed to soar from the waters.

"We're obviously concerned by those reports," State Department deputy spokesman Mark Toner said at a regular briefing.

The U.S. and its partners in the stalled six-party talks with the North continue to send a "very strong and clear and consistent message" to Pyongyang to "refrain from any violations of the U.N. Security Council resolutions, or any other actions that raise tensions in the region, and threaten international peace and security," he said.

In May, North Korea claimed it successfully carried out an SLBM test underwater, renewing tensions on the Korean Peninsula amid concerns that the North's SLBM capability, if fully developed, would pose a serious threat because its mobile nature would make it very difficult to detect preparations for a launch.

But experts said it was believed not to be a full-scale test, but an "ejection" test conducted in an early stage of developing SLBM capabilities. U.S. officials said the North also exaggerated progress and is many years away from developing an SLBM.

Under U.N. resolutions, the North is banned from any ballistic missile activity. (Yonhap)