North Korea conducted its ninth weapons test of the year on Saturday, firing a suspected ballistic missile toward the sea to the east of the Korean peninsula just days before South Korea's presidential election.
The launch drew condemnation from governments in the United States, South Korea, and Japan, which fear the North is preparing to conduct a major weapons test in coming months.
With denuclearization talks stalled, North Korea conducted a record number of missile launches in January, and after a pause for most of February, resumed tests with a launch on Feb. 27.
It appears to be preparing to launch a spy satellite in the near future, and has suggested it could resume testing of nuclear weapons or its longest range intercontinental ballistic missiles (ICBMs) for the first time since 2017.
"The significant pace at which North Korea is developing its missile-launching technology is not something our country and the surrounding regions can overlook," Japan's Defense Minister Nobuo Kishi said after the latest launch, Reuters reported.
In South Korea, where citizens are already casting early votes ahead of Wednesday's presidential election, the National Security Council (NSC) condemned North Korea's "unprecedented repeated firing of ballistic missiles" as going against peace and stability on the Korean Peninsula.
South Korea will "even more closely monitor North Korea's nuclear and missile-related facilities" including its main nuclear reactor facility at Yongbyon and the Punggye-ri nuclear weapons test side, the NSC said, according to a statement from the presidential Blue House.
It was not immediately clear what prompted the increased monitoring of the nuclear sites.
On Friday, the US-based 38 North project, which monitors North Korea, said operations at Yongbyon are in full swing, producing fuel for potential nuclear weapons and an expansion of its nuclear production facilities.
Punggye-ri has been shuttered since North Korea declared a self-imposed moratorium on nuclear weapons tests in 2018. Leader Kim Jong Un, however, has said he no longer feels bound by that moratorium as denuclearization talks are stalled.
South Korea has reported a series of small, natural earthquakes near Punggye-ri this year, highlighting what experts say is geological instability caused by the last and largest nuclear test in 2017. Experts have also said that instability would not necessarily prevent North Korea from resuming tests at the site.
The US State Department condemned the latest launch as a violation of United Nations Security Council resolutions, which have imposed sanctions on North Korea over its weapons programs.
The launch demonstrates the threat that North Korea's illicit weapons of mass destruction and missile programs pose to the its neighbors and the region as a whole, a State Department spokesperson said.
The South Korean military said Saturday's launch came from a location near Sunan, where Pyongyang's international airport is located. The region has been the site of previous tests, including the last launch on Feb. 27, when North Korea said it tested systems for a reconnaissance satellite.
Kishi said the North Korean projectile reached a height of 550 km (340 miles) and flew 300 km (190 miles), similar to the South Korean military's estimate of 560 km height and 270 km distance.
The launch underscores the challenges facing whoever wins Wednesday's presidential election in South Korea.
Both leading candidates have said they would unveil roadmaps to try to jumpstart stalled talks, but have also raised the prospect of a harder line ranging from more openly calling the North's missile tests "provocations" to developing more military capacity for preemptive strikes if necessary to counter an imminent threat.
Analysts say North Korea could use the upcoming presidential transition in South Korea or a big national holiday on April 15 to launch a satellite or test fire a major new missile or other weapon.
"The timing of North Korea's missile testing may seem odd to us, given the global focus on Ukraine," Jean Lee, a fellow at the Washington-based Wilson Center, said on Twitter. "But it makes perfect sense in North Korea, where scientists are focused on perfect new weapons for Kim to show off at a big military parade in mid-April."
The United States has said it is open to talks without preconditions, but Pyongyang says talks are only possible after Washington and its allies drop hostile policies.