North's Sunday morning missile comes before joint South-U.S. naval exercises

North Korea fired a short-range ballistic missile into waters east of the Korean Peninsula on Sunday morning, South Korean military authorities reported.

Defense Minister Lee Jong-sup, third from left, tours the aircraft carrier USS Ronald Reagan in Busan on Saturday. The Reagan arrived in Busan on Friday. [NEWS1]

North Korea fired a short-range ballistic missile into waters east of the Korean Peninsula on Sunday morning, South Korean military authorities reported.

According to Seoul's Joint Chiefs of Staff (JCS), the South Korean military detected the launch of a single short-range ballistic missile from Taechon, North Pyongan Province, toward the East Sea at 6:53 a.m.

South Korean and U.S. military authorities said that the missile flew approximately 600 kilometers (373 miles) at Mach 5, reaching an apex of 60 kilometers before descending into the sea.

A military official who spoke on the condition of anonymity to the JoongAng Ilbo said South Korean authorities believe the missile fired by the North was a KN-23 missile, which is widely believed to be based off of the Russian Iskander short-range missile. The official added that the missile was likely fired from a mobile transporter erector launcher system.

The South Korean military said it is maintaining full preparedness while closely cooperating with the United States and strengthening its surveillance and defensive posture.

Observers believe the missile launch is a demonstration of force by the North in response to planned South Korea-U.S. joint naval exercises, and particularly the arrival of the aircraft carrier USS Ronald Reagan in Busan on Friday.

The nuclear-powered submarine USS Annapolis, which carries Tomahawk cruise missiles capable of striking the entire territory of North Korea, is also expected to participate in the joint naval drills.

The carrier strike group led by the USS Ronald Reagan will take part in exercises with the South Korean Navy in the East Sea from Sept. 26 to 29.

While it is unlikely that the North would target U.S. or South Korean naval forces with KN-23 short-range missiles while they are conducting drills, both the KN-23 as well as hypersonic cruise missiles tested by the North earlier this year are capable of changing their trajectories mid-flight, making their interception difficult for existing naval defense systems.

The Aegis ballistic missile defense system (BMD) is currently under development by the United States Department of Defense Missile Defense Agency program to provide missile defense against short to intermediate-range ballistic missiles.

Aegis BMD is an expansion of the Aegis Combat System deployed on warships, designed to intercept ballistic missiles in post-boost phase and prior to re-entry.

Sunday’s missile test by North Korea came soon after Seoul’s military said it detected signs that Pyongyang could be preparing to test a submarine-launched ballistic missile (SLBM) ahead of a visit by U.S. Vice President Kamala Harris.

The South Korean military detected preparations this week in Sinpo, South Hamgyong Province, an assessment that was broadly in line with a report by U.S.-based think tank 38 North that cited commercial satellite imagery.

The South Korean presidential office released a statement on Saturday saying President Yoon Suk-yeol is aware of signs and movements that could suggest a provocation by North Korea, including an SLBM launch.

Sunday's ballistic missile launch comes 113 days after the North fired eight short-range ballistic missiles (SRBMs) all on the same day, June 5. It is also the fifth missile launch since the inauguration of South Korean President Yoon Suk-yeol in May.

Harris is set to meet with leaders of Japan and South Korea during her visit to the region next week.

BY MICHAEL LEE [lee.junhyuk@joongang.co.kr]