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 week the country would continue to build up its military capabilities.

In its latest apparent launch, an unidentified projectile was fired into the sea east of the peninsula, the South Korean Joint Chiefs of Staff said in a statement, without immediately providing further details.

Japan's coast guard said it spotted what appeared to be ballistic missiles fired from North Korea, warning vessels in the area to not approach any suspicious objects.

In 2021, nuclear-armed North Korea said it 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.

The 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.

At the end of a key meeting of the ruling Workers' Party last week, where Kim spoke about building up defences, he did not mention the United States at all.

Instead of the policy positions on diplomacy for which Kim's New Year statements have been closely watched in recent years, he focused on food security and development in an extensive speech.

But he said Pyongyang would continue to boost its capabilities keeping in mind "the military environment of the Korean peninsula" and the changing international situation.

North Korea is under multiple sets of international sanctions over its nuclear and ballistic missile programmes, which have progressed rapidly under Kim.

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

The worsening economic situation during the pandemic, however, has not blunted those programmes, and North Korea has continued to pursue weapons development, a UN report said in October.

Concerns have grown about a full-blown food crisis in North Korea, and a United Nations human rights expert warned in October that the most vulnerable were "at risk of starvation".