North Korea launched an unidentified projectile off its west coast Tuesday, South Korea's military said, in what appeared to be the North's latest weapons test this year.

A brief dispatch from South Korea's Joint Chiefs of Staff gave no further details.

It followed another launch by the North on April 19, in which it fired multiple short-range missiles in what state-media described as a demonstration of cluster bomb warheads.

North Korean leader Kim Jong Un has focused on expanding his nuclear and missile arsenals since nuclear diplomacy with US President Donald Trump collapsed in 2019. Trump has repeatedly expressed his desire to resume talks with Kim, but Pyongyang has so far ignored the overtures and urged Washington to drop demands for the North's nuclear disarmament as a precondition for talks.

Kim has taken an increasingly hardline stance toward South Korea, which he has declared his country's permanent and most hostile enemy while diplomacy is stalled and tensions rise over his nuclear ambitions.

The launch came hours after South Korean President Lee Jae Myung during a Cabinet meeting called for stronger efforts to advance the country's military. He emphasised artificial intelligence and drone capabilities and the potential acquisition of a nuclear-powered submarine, an issue that has been part of his diplomacy with Washington.

Lee did not specifically comment on the threats posed by North Korea, but stressed the importance of South Korea demonstrating the "resolve to take responsibility for and protect our own security ourselves," saying such a posture would also strengthen the country's alliance with the United States.