North Korea has flight-tested a ballistic missile that was probably fired from a submarine, South Korea's military said.

The launch on Saturday continues a provocative streak in weapons demonstrations that may culminate with a nuclear test in the coming weeks, according to South Korean officials.

South Korea's Joint Chiefs of Staff said the missile came from waters near the eastern port city of Sinpo, where North Korea has a major shipyard building submarines.

It said the short-range missile flew 600 kilometres at a maximum altitude of 60 kilometres but did not provide details about the submarine that would have been involved in the launch.

South Korean and US intelligence officials were analysing the launch, the military said, describing it as a clear violation of UN Security Council resolutions and a "serious threatening act that harms international peace and stability".

Japan also said the projectile was a short-range ballistic missile and Defence Minister Nobuo Kishi said North Korea's recent development in nuclear missile-related technology and repeated missile launches threatened the region and the international community.

Although there were no reports of any damage, Japanese Prime Minister Fumio Kishida ordered officials to prepare for all "unforeseeable situations" and secure the safety of aircraft and ships. 

It was apparently North Korea's first demonstration of a submarine-launched ballistic missile system since last October — its first in two years — when it fired a new short-range missile from the 8.24 Yongung submarine.

On Wednesday, the South Korean and Japanese militaries detected a suspected ballistic missile fired from near the capital, Pyongyang.

Both exercises come ahead of the inauguration on Tuesday of South Korean President-elect Yoon Suk Yeol, who has vowed to take a tougher approach over the North's nuclear ambitions.

North Korea has fired missiles 15 times in 2022, including its first test of an intercontinental ballistic missile since 2017 in March, demonstrating a potential range to reach the entirety of the US mainland.

North Korea has been exploiting a favourable environment to push forward its weapons program with the UN Security Council divided and effectively paralysed over Russia's war on Ukraine.

The unusually fast pace in testing activity underscores brinkmanship aimed at forcing the US to accept the idea of the North as a nuclear power and remove crippling sanctions, experts say.

North Korean leader Kim Jong Un punctuated his recent missile tests with statements warning that the North could proactively use its nuclear weapons if threatened or provoked.

Mr Kim made one of those statements during an April 25 parade in Pyongyang, where he showcased the most notable weapons in his military nuclear program, including ICBMs.

They appeared to be a new type of missile designed to be fired from submarines which were believed to be larger than previous models.

Later on Saturday, South Korea's National Intelligence Service chief, Park Jie-won, said that North Korea may conduct a nuclear test between Mr Yoon's inauguration on Tuesday and US President Joe Biden's visit to Seoul later this month.

Mr Park told the Yonhap news agency that North Korean nuclear warheads — if modified — could provide a threat to both South Korea and Japan.

ABC/AP