Meanwhile, the South Korean military said on Monday that North Korea had launched one unidentified missile from a submarine, according to Yonhap.
The missile was launched on Sunday from North Korea’s eastern coastal city of Sinpo, South Korea’s Joint Chiefs of Staff (JCS) said.
The missiles were test-fired from the 8.24 Yongung submarine during an underwater drill held on Sunday morning, Yonhap said on Monday citing North Korea’s official Korean Central News Agency (KCNA).
The missiles hit targets in the Sea of Japan after "traveling the 1,500 km-long [932 mile-long] eight-shaped flight orbits for 7,563 to 7,575 seconds," KCNA said as quoted by Yonhap, adding that the drill confirmed the reliability of the new weapon system and "verified the current operation posture of the nuclear war deterrence means."
"While strengthening its monitoring and vigilance, our military is maintaining a full readiness posture in close cooperation with the United States," the JCS said in a statement quoted by Yonhap on Monday.
Meanwhile, KCNA reported that the test was to confirm "the reliability of the weapon system and inspected and judged the operational posture of the underwater-to-ground attack of the submarine units."
The agency also reported that the drills show the Korean People's Army ability to counter the "military moves of the US imperialists and south [sic] Korean puppet traitors."
On March 9, North Korea fired a short-range ballistic missile. At the end of February, North Korea test-fired two missiles from a multiple launch rocket system (MLRS). Also last month, North Korea test-fired the Hwasong-15 intercontinental ballistic missile (ICBM). The launch was carried out from the Pyongyang International Airport and the missile reached a maximum altitude of 5,768 kilometers (3,584 miles), covering a distance of 989 kilometers, according to the South Korean military.