South Korea and the U.S. are capable of detecting and countering North Korea's sea-based ballistic missiles, the U.S. navy chief said Friday, stressing that if the North launches any provocations they will be met with a "proportional" response.

   North Korea is believed to be preparing for another test of a submarine-launched ballistic missile in the near future following its claim of a successful SLBM test in May, according to recent U.S. news reports.

   Such tests could indicate significant headway in the communist country's nuclear weapons capabilities, particularly sea-based ones that are harder to detect and counter.

   "I think that's destabilizing capability, but we do have capabilities as well to detect and counter such threats," the Chief of Naval Operations Adm. John Richardson told a group of reporters in Seoul. "So in this scenario we would want to enhance our cooperation with South Korea to make sure our posture is well to counter such threats."

   Richardson is in Seoul as part of a four-nation trip, the first overseas outing since he took office a month earlier.

   Seoul is the second leg of the trip, following Japan. He will fly to Bahrain on Saturday and then move to Italy before returning home.

   North Korea's expected SLBM test could be "unpredictable and destabilizing," and the U.S. is ready to respond to the action, the admiral said, declining yet to discuss the timing and other related information of the test.

   He also stressed if North Korea launches any kinds of provocations "the response would be proportional."

   The admiral suggested that joint naval exercises between South Korea and Japan would greatly help the trilateral military cooperation also involving the U.S. in deterring North Korean threats.

   "If we are trying to provide a situation that deters North Korea from provocative types of behaviors, that type of trilateral cooperation provides more responsive options and better deterrence posture." he said.

   "There are advantages to that type of cooperation," he added, calling for more military collaboration between the two Asian countries entangled in history-related diplomatic tensions.

   Richardson also indirectly called for South Korea's participation in U.S. patrolling activities in the tension-ridden South China Sea.

   "The U.S. and South Korea are global nations, we have global interests ... we should act in support of the rules that govern global trade, global prosperity and global maritime traffic," the admiral noted, adding that no one should be surprised that global nations with global trade would be interested in preserving and supporting the international law that allows them as much access as possible.  (Yonhap)