SEOUL — North Korea has fired at least one ballistic missile into waters off the coast of Japan, BBC reported quoting South Korean and Japanese military sources.

The latest test in a series, which according to analysts could have been a submarine-launched weapon, comes as South Korea, Japan and US intelligence chiefs reportedly meet in Seoul to discuss North Korea.

In recent weeks, Pyongyang has embarked on a flurry of tests of what it claims to be hypersonic and long-range cruise missiles, and anti-aircraft weapons.

Some of these tests violate strict international sanctions.

North Korea is specifically prohibited by the United Nations from testing ballistic missiles as well as nuclear weapons.

On Tuesday South Korea's Joint Chiefs of Staff said one missile was launched from the port of Sinpo, in the east of North Korea where Pyongyang usually bases its submarines. It landed in the East Sea, also known as the Sea of Japan.

The "unidentified ballistic missile" was fired from Sinpo into the sea east of the peninsula, Seoul's Joint Chiefs of Staff said in a statement.

"South Korean and US intelligence are closely analysing for additional detail," it added.

Sinpo, where the missile was fired from, is a major naval shipyard and satellite photographs have previously shown submarines at the facility.

Japan's Prime Minister Fumio Kishida said there were two ballistic missiles, calling the launches "very regrettable".

North Korea has pressed ahead with its missile tests as South Korea also develops its own weapons, in what observers say has turned into an arms race on the Korean peninsula.

Pyongyang is known to be developing a submarine-launched ballistic missile (SLBM) and previously carried out an underwater launch, although analysts said that one was likely to have been from a submerged platform rather than a submarine.

"There is a high possibility the North launched an SLBM," said Shin Beom-chul, a researcher at the Korea Research Institute for National Strategy.

South Korea recently unveiled a submarine-launched missile, and is holding what is said to be its largest defence exhibition ever this week. Seoul is also due to launch its own space rocket soon.

North and South Korea technically remain at war as the Korean War, which split the peninsula into two countries, ended in 1953 with an armistice.

North Korean leader Kim Jong-un said last week that he did not wish for war to break out on the Korean peninsula again, but said his country needed to continue developing weapons for self-defence against enemies, namely the US which he accused of hostility.

In the last 24 hours, the US envoy to North Korea Sung Kim has reiterated the stance of the Biden administration that it is open to meeting with North Korea without pre-conditions.

Previous talks between the US and North Korea broke down due to fundamental disagreements on denuclearisation.

The US wants North Korea to give up its nuclear weapons before sanctions can be eased, but North Korea has so far refused. — Agencies