South Korea successfully tested a submarine-launched ballistic missile (SLBM) on Wednesday, becoming the first country without nuclear weapons to develop such a system as it aims to better counter North Korea's growing capabilities.

South Korea's missile test came the same day as North Korea fired a pair of ballistic missiles off its east coast, breaching U.N. sanctions and ratcheting up tension just days after testing a cruise missile with possible nuclear capabilities.

President Moon Jae-in attended an underwater ejection test of the SLBM aboard the new 3,000-ton Dosan Ahn Chang-ho submarine commissioned last month, his office said.