Seoul, South Korea —fired two ballistic missiles into waters off its eastern coast on Wednesday afternoon, two days after claiming to have in a resumption of its weapons displays after a six-month lull. South Korea responded to the latest provocation with landmark weapons tests of its own just hours later, ratcheting up tension on the nuclear-armed Korean Peninsula where thousands of American troops are based.
South Korea's Joint Chiefs of Staff said the North launched the two missiles on Wednesday from a site in the center of the country.
Hours later, South Korea said it had successfully carried out a first-ever test of an underwater-launched missile, making the country one of just seven in the world with the proven capability to fire a ballistic missile from a submarine, along with the U.S., Russia, China, Britain, France and India.
South Korea's Agency for Defense Development also announced in a statement that the country had tested on Wednesday a new fighter-jet launched, long range air-to-surface missile, and it touted development of a new supersonic missile with "a higher speed than existing missiles, making it very difficult for enemy ships to respond, which further improves the missile's survivability and destructive power."
The agency said that new missile was "expected to become a core force that can more effectively respond to forces approaching Korea's territorial waters."
President Moon Jae-in's office said in a statement that Moon had observed the test of a domestically built submarine-launched ballistic missile on Wednesday afternoon. It said the missile flew a previously set distance and hit a designated target.
Video released by the South Korean Ministry of Defense showed a submarine sailing at the surface, and then cut to a clip that showed a missile emerging from beneath the sea and flying skyward.
After Moon lauded the South's growing missile capabilities as "sure deterrence" against future North Korean provocations, the powerful sister of North Korea's leader threatened a "complete destruction" of relations between the two countries.
Japanese Prime Minister Yoshihide Suga said earlier that the North Korean missiles had landed outside of Japan's Exclusive Economic Zone in waters between northwest Japan and the Korean Peninsula.
North Korea's latest tests "threaten the peace and safety of Japan and the region and are absolutely outrageous," Suga said. "The government of Japan is determined to further step up our vigilance and surveillance to be prepared for any contingencies."
The U.S. military's Indo-Pacific Command said in a statement that it was "aware of the missile launch" by North Korea and was "consulting closely with our allies and partners."
"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 [North Korea's] illicit weapons program. The U.S. commitment to the defense of the Republic of Korea [South Korea] and Japan remains ironclad," the statement said.
There was no immediate U.S. statement on South Korea's submarine-fired missile test, but the two — countries coordinate closely and America has maintained a robust troop presence in the South approximately 30,000 personnel — since hostilities in the Korean War ended without a treaty in the 1950s.
Seoul said South Korean and U.S. intelligence authorities were analyzing details about the North Korean launches.
The South Korean joint chiefs' statement added that the South had boosted its anti-North Korea surveillance posture. The statement was released prior to the announcement of South Korea's own missile test on Wednesday.
North Korea had said Monday that it tested a newly developed cruise missile twice over the weekend. North Korean state media described the missile as a "strategic weapon of great significance," implying they were developed with the intent to arm them with nuclear warheads.
According to North Korean accounts, the missile flew about 930 miles, a distance putting all of Japan — including U.S. military installations in that country — within reach.
Many experts say the weekend tests suggest that North Korea is pushing to bolster its weapons arsenal amid a deadlock in nuclear diplomacy between Pyongyang and Washington.
Wednesday's launches came as Chinese Foreign Minister Wang Yi was in Seoul for meetings with South Korean President Moon Jae-in and other senior officials to discuss the stalled nuclear diplomacy with the North.
It's unusual for North Korea to make provocative launches when China, its last major ally and biggest aid provider, is engaged in a major diplomatic event.
Moon's office said Moon told Wang he appreciates China's role in the international diplomatic push to resolve the North Korean nuclear standoff and asked for Beijing's continuing support.
Wang said Beijing will continue to support the denuclearization of the Korean Peninsula and improved ties between the Koreas, and also called for further development in relations with Seoul.
The nuclear diplomacy between the United States and North Korea has stalled since 2019, when the Americans rejected the North's demand for major sanctions relief in exchange for dismantling an aging nuclear facility. Kim's government has so far threatened to build high-tech weapons targeting the United States and rejected the Biden administration's overtures for dialogue, demanding that Washington abandon its "hostile" policies first.
The North's resumption of testing activity is likely an attempt at pressuring the Biden administration over the diplomatic freeze after Kim failed to leverage his arsenal for economic benefits during the presidency of Donald Trump.
North Korea ended a yearlong pause in ballistic tests in March by firing two short-range ballistic missiles into the sea, continuing a tradition of testing new U.S. administrations with weapons demonstrations aimed at measuring Washington's response and wresting concessions.
North Korea still maintains a self-imposed moratorium on nuclear and long-range missile tests, a sign that it may not want to completely scuttle the nuclear negotiations with the United States.