The early-morning launch came as the UN Security Council met in New York to discuss last week's test of what Pyongyang called a hypersonic missile, although Seoul has cast doubt on that claim.

"Our military detected a suspected ballistic missile fired by North Korea from land towards the East Sea at around 7:27 a.m. today," Seoul's Joint Chiefs of Staff said in a statement.

Japanese Prime Minister Fumio Kishida confirmed the development, telling reporters that North Korea had launched "an object that could be a ballistic missile".

Pyongyang's second test in a week came after six countries, including the United States and Japan, urged North Korea Monday to cease "destabilising actions" ahead of the UN Security Council closed-door meeting.

"It is extremely regrettable that North Korea continues to launch missiles," Kishida said.

France, Britain, Ireland and Albania joined the call for North Korea to "engage in meaningful dialogue towards our shared goal of complete denuclearization".

Analysts said Pyongyang had likely planned the latest launch to coincide with the UN meeting.

"North Korea continues testing to diversify its nuclear arsenal, but it timed the launch on the day of the UNSC meeting to maximise its political impact," Shin Beom-chul, a researcher at the Korea Research Institute for National Strategy, told AFP.

The frequency of testing indicated Pyongyang could be fitting in the launches ahead of the Beijing Olympics next month, said Park Won-gon, a professor at the Ewha Womans University in Seoul.

North Korea has been barred from the Beijing Winter Olympics after skipping the pandemic-delayed Tokyo Games over Covid-19 concerns, a move Pyongyang has blamed on "hostile forces".

- Military build-up -

In the decade since Kim Jong Un took power, North Korea has seen rapid progress in its military technology at the cost of international sanctions.

Despite severe economic difficulties during the coronavirus pandemic, Kim said last month the country would continue to build up its military capabilities.

In 2021, nuclear-armed North Korea said it had successfully tested a new type of submarine-launched ballistic missile, a long-range cruise missile, a train-launched weapon, and what it described as a hypersonic warhead.

South Korea has cast doubts over Pyongyang's hypersonic claims, saying last week's test represented limited progress from the regime's existing ballistic missiles.

The tests come as North Korea has refused to respond to US appeals for talks.

At a key meeting of North Korea's ruling party last month, leader Kim Jong Un vowed to continue building up the country's defence capabilities, without mentioning the United States.

Instead of the policy positions on diplomacy, for which Kim's New Year statements are closely watched, he focused on food security and economic development in a lengthy speech.

Dialogue between Washington and Pyongyang remains stalled, following the collapse of talks between Kim and then president Donald Trump in 2019.

Under Trump's successor Joe Biden, the United States has repeatedly declared its willingness to meet North Korean representatives, while saying it will seek denuclearisation.

But Pyongyang has so far dismissed the offer, accusing Washington of pursuing "hostile" policies.

North Korea is under multiple sets of international sanctions over its nuclear and ballistic missile programmes.

The impoverished nation has also been under a rigid self-imposed coronavirus blockade that has hammered its economy.