North Korea steps up UN campaign for return of seized ship

North Korea has stepped up a diplomatic campaign at the United Nations to secure the release of a cargo ship seized by the United States, warning there could be "undesirable consequences" if no action is taken.

North Korean Ambassador Kim Song offered the warning in a meeting with UN political chief Rosemary DiCarlo on Wednesday to press Pyongyang's demands that the world body intervene, the North Korean mission said.

The United States announced on May 9 that it had impounded the state-owned Wise Honest, arguing that it was being used to export North Korean coal, in violations of UN sanctions over its banned nuclear weapons and ballistic missile programs.

The seizure came amid heightened tensions after Pyongyang's recent short-range missile launches, and with talks deadlocked since the collapse of the Hanoi summit between President Donald Trump and North Korean leader Kim Jong Un.

The Wise Honest, one of the largest cargo ships in North Korea's fleet, was detained in Indonesia in April 2018, loaded with North Korean coal.

After it was seized by the US, the ship was taken to American Samoa, where it is docked at Pago Pago.

The North Korean ambassador wrote to UN Secretary-General Antonio Guterres on May 18 to ask for "urgent measures" to return the Wise Honest.

A UN spokesman declined to comment on the meeting between Kim and DiCarlo, the under-secretary-general for political affairs, but said the UN sanctions committee should address the matter.

The Security Council will on Thursday hear a report from the sanctions committee on North Korea.