(ATTN: ADDS more details in paras 6, 15, 22; TRIMS)
By Oh Seok-min and Choi Soo-hyang
SEOUL, Sept. 15 (Yonhap) -- North Korea fired two short-range ballistic missiles into the East Sea on Wednesday, South Korea's Joint Chiefs of Staff (JCS) said, gradually ratcheting up tensions just days after successfully test-firing a newly developed long-range cruise missile.
The projectiles were fired from the central county of Yangdok at 12:34 p.m. and 12:39 p.m., respectively, and flew around 800 kilometers at a maximum altitude of around 60 km, the JCS said.
"South Korean and U.S. intelligence authorities are analyzing details for additional information," the JCS said in a release. "Our military is maintaining a full readiness posture in close cooperation with the United States."
Government sources said the tested missiles appear to be an upgraded version of the North's KN-23 Iskander ballistic missile, as the military detected the so-called pull-up maneuver over the course of their flight.
Wednesday's launches came two days after the North announced it successfully test-fired a new type of long-range cruise missile over the weekend, calling it "a strategic weapon of great significance" to indicate its nuclear capability.
Seoul's top security officials expressed "deep concern" over a series of missile launches by the North "at a time when ensuring the stable situation is urgently needed, according to the presidential office Cheong Wa Dae.
Under the U.N. Security Council resolutions, North Korea is banned from ballistic missile activity, while cruise missiles are not subject to sanctions.
The U.S. military said the launches show the destabilizing impact of the North's illicit weapons program.
"While we have assessed that this event does not pose an immediate threat to U.S. personnel or territory, or to our allies, the missile launch highlights the destabilizing impact of the DPRK's illicit weapons program," the U.S. Indo-Pacific Command said in a statement.
DPRK is the acronym of the North's official name, the Democratic People's Republic of Korea.
In a separate statement, the U.S. Forces Korea (USFK) said, "This activity highlights DPRK's continuing focus on developing its military program and the threat it poses to Northeast Asia and the international community."
"We will continue to monitor the situation, consult closely with our South Korean allies and remain committed to providing a combined robust defense posture to protect the ROK against any threat or adversary," it added.
The latest test is the second ballistic missile launch by the North so far this year, and its fifth known major weapons test if the cruise missile tests are taken into account.
The North's last ballistic missile test took place on March 25, when it fired two short-range missiles into the East Sea, believed to be an upgraded version of its KN-23 Iskander missile.
Experts said that Pyongyang could have tried to show its missile prowess in response to South Korea's powerful ground-based Hyunmoo-4 missile through the latest launches. The Hyunmoo-4 was unveiled in 2020.
"The North said after the March test that the new 'tactical guided projectile' has a 2.5-ton warhead. If you reduce the payload, the missile can fly farther," missile expert Ryu Sung-yeop from the Korea Research Institute of Military Affairs said.
During the March test, the missiles flew around 450 km at an altitude of about 60 km, according to the JCS.
"Or the North could make the missile bigger to secure a longer flight range. The Hyunmoo-4 has a 2-ton payload and a maximum range of 800 km," he noted.
Shin Jong-woo, a senior analyst at the Korea Defense Security Forum in Seoul, also said that the latest test appears to have been intended to verify the reliability of the Iskander missile, as the North has often brought its weapons to inland regions to fly them across its territory into the East Sea.
Wednesday's test coincided with South Korea's successful test of an indigenous submarine-launched ballistic missile (SLBM) from the newly launched 3,000 ton-class Dosan Ahn Chang-ho submarine. Some have raised concerns over an arms race between the two Koreas.
The latest firing came as Chinese Foreign Minister Wang Yi was in South Korea for talks with his South Korean counterpart, Chung Eui-yong.
The two sides said that such military actions would not be helpful for inter-Korean ties, and vowed to work closely for an early resumption of dialogue involving North Korea, according to a Seoul official.
Denuclearization talks between the U.S. and North Korea have stalled. The Biden government has said it is ready to hold talks with the North anywhere, at anytime, but the communist country has remained unresponsive to U.S. overtures.
On Tuesday, U.S. Special Representative to North Korea Sung Kim expressed his country's willingness to cooperate with Pyongyang on humanitarian issues "regardless of progress on denuclearization," after talks with his South Korean and Japanese counterparts, Noh Kyu-duk and Takehiro Funakoshi, respectively, in Tokyo.
Last month, North Korea warned of a "major security crisis" in protest against the combined summertime military exercise between South Korea and the U.S.
It severed all inter-Korean communication lines, and has also shown signs of restarting a plutonium-producing nuclear reactor at its mainstay Yongbyon complex.