The US on Wednesday condemned North Korea and urged Pyongyang to sit down for talks after South Korea's military said it fired what is "presumed to be a ballistic missile" into the sea.
"This launch is in violation of multiple UN Security Council Resolutions and poses a threat to the DPRK's neighbours and the international community," a State Department spokesperson said, referring to the North by its official name, the Democratic People's Republic of Korea.
"We remain committed to a diplomatic approach to the DPRK and call on them to engage in dialogue," the official said.
In the decade since Supreme Leader Kim Jong-un took power, North Korea has made rapid progress in its military technology at the cost of international sanctions.
Despite severe economic difficulties during the coronavirus pandemic, Mr Kim said last week that the country would continue to build up its military capabilities.
In its latest apparent test, 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.
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.
The dialogue between Washington and Pyongyang remains stalled, following the collapse of talks between Mr Kim and former president Donald Trump in 2019.
Under Mr Trump's successor, Mr Biden, the US has repeatedly declared its willingness to meet North Korean representatives, while saying it will seek denuclearisation.
At the end of a key meeting of the ruling Workers' Party last week, during which Mr Kim spoke about building up defences, he did not mention the US at all.
Instead of the policy positions on diplomacy for which Mr 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 defence 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 Mr 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 UN human rights expert said in October that the most vulnerable were “at risk of starvation".