North Korea has fired at least one ballistic missile into the sea from its east coast, South Korean officials say.
The launch took place on Tuesday and follows a series of other projectiles being fired from the country in recent weeks.
One ballistic missile was launched about 10:17 a.m. local time from the area of Sinpo, South Korea's Joint Chiefs of Staff said, where North Korea keeps submarines as well as equipment for test firing submarine-launched ballistic missiles.
The missile flew about 430-450 kilometres to a maximum altitude of 60 kilometres, Yonhap news agency reported, citing an unnamed source.
It was not immediately clear whether the missile was fired from a submarine or from a submersible test barge, as in most previous tests.
"Our military is closely monitoring the situation and maintaining readiness posture in close cooperation with the United States, to prepare for possible additional launches," JCS said in a statement.
Japanese Prime Minister Fumio Kishida said that two ballistic missiles had been detected, and that it was "regrettable" that North Korea had conducted a string of missile tests in recent weeks.
The most recent launch came as the intelligence chiefs of the US, South Korea, and Japan were due to meet in Seoul to discuss the standoff with North Korea, Yonhap news agency reported, citing a government source.
Representatives of hundreds of international companies and international militaries were gathered in Seoul for the opening ceremonies of the International Aerospace and Defence Exhibition.
It is set to be South Korea's largest defence expo ever, with displays of next-generation fighter aircraft, attack helicopters, drones, and other advanced weapons, as well as space rockets and civilian aerospace designs.
Just days earlier the leader of the secretive state Kim Jong-un showed off his country’s latest nuclear missiles and accused the US and South Korea of creating tensions.
In a speech carried by state news, Kim said he was increasing his military strength as an act of self-defence.
He claimed that Pyongyang’s weapons development was necessary in the face of hostile policies from the US and a military build-up in South Korea, according to a report by state news agency KCNA.
A number of separate launches have also been carried out in recent weeks amid stalled denuclearisation talks with the United States.
Last month ballistic and cruise missiles with potential nuclear applications were also launched.
Japanese Prime Minister Yoshihide Suga called that ballistic missile launch "outrageous", and strongly condemned the action as a threat to peace and security of the region.
Pyongyang has been steadily developing its weapons programme amid a standoff over talks aimed at dismantling its nuclear and ballistic missile programmes in return for US sanctions relief.
Washington is currently offering sanctions relief in exchange for the country's "rapid denuclearisation".
Elsewhere, neighbouring China was reported to have recently tested a terrifying nuclear-capable hypersonic missile which orbited the globe before returning to Earth, taking US intelligence officials by surprise.
The Chinese military was said to have launched a rocket carrying a hypersonic glide vehicle that flew through low-orbit space, circling the globe.
It then cruised towards its target, which it missed by about two dozen miles.
A report, citing five unnamed intelligence sources, said the military had launched its Long March rocket in August.
