North Korea fired two projectiles presumed to be short-range ballistic missiles on Monday, the South Korean military said, in Pyongyang's fourth launch in two weeks as the country ramps up missile tests.

The projectiles were fired in an easterly direction from the Sunan Airport area in Pyongyang shortly before 9 a.m., the Joint Chiefs of Staff said, adding they traveled about 380 kilometers and reached an altitude of around 42 km.

Japanese Defense Minister Nobuo Kishi said two ballistic missiles were launched at 8:49 a.m. and 8:52 a.m., and are believed to have fallen off North Korea's eastern coast and outside Japan's exclusive economic zone in the Sea of Japan.

Japanese Defense Minister Nobuo Kishi (C) meets the press in Tokyo on Jan. 17, 2022, saying North Korea fired two ballistic missiles eastward earlier in the day. (Kyodo) ==Kyodo

Kishi told reporters the missiles flew around 300 km if they had followed a normal trajectory, adding they reached a maximum altitude of around 50 km.

The Japanese government condemned the launch, with Chief Cabinet Secretary Hirokazu Matsuno saying it "threatens the peace and security of our country, the region and the international community."

The government also lodged a protest with North Korea through the Japanese Embassy in Beijing.

Prime Minister Fumio Kishida instructed the government to provide accurate information to the public, check the safety of vessels and aircraft, and be ready to respond to any unexpected development.

"It is very regrettable," Kishida said at a meeting of lawmakers. "We must advance our security debate steadily, including the National Security Strategy," he added, referring to Japan's long-term security guidelines that the government aims to revise by year-end.

Pyongyang launched what it says were newly developed hypersonic missiles on Jan. 5 and last Tuesday, while launching two suspected short-range ballistic missiles last Friday. It said the Friday launch was a firing drill for a railway-borne missile regiment.

The U.S. government also condemned the latest North Korean move.

"These launches are in violation of multiple U.N. Security Council resolutions and pose a threat to the DPRK's neighbors and the international community," a State Department spokesperson said, referring to the acronym of the Democratic People's Republic of Korea, North Korea's official name.

U.N. Security Council resolutions ban Pyongyang from employing ballistic missile technology.

The U.S. military's Indo-Pacific Command said the missile launches "highlight the destabilizing impact of the DPRK's illicit weapons program," adding in a statement that the U.S. commitment to the defense of South Korea and Japan remains ironclad.

Chief Cabinet Secretary Hirokazu Matsuno holds a press conference at the prime minister's office in Tokyo on Jan. 17, 2022. (Kyodo)

Responding to the launch, South Korean President Moon Jae In said he will "make utmost efforts to manage the situation on the Korean Peninsula," according to presidential office spokeswoman Park Kyung Mee.

Japan's defense minister, Kishi, said North Korea has clearly been trying to improve its missile-related technology and operational capabilities, including enhancing secrecy, immediacy and capability to mount a surprise attack, in order to make it hard to detect signs of a launch.

During phone talks later Monday, senior officials in charge of the North Korea issue from Japan, the United States and South Korea expressed "strong concerns" about Pyongyang's missile and nuclear development while agreeing to maintain close cooperation among them, according to the Japanese Foreign Ministry.

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