United Nations Secretary-General Antonio Guterres has proclaimed unwavering UN commitment to a fully denuclearised North Korea, as a divided Security Council allows more room for the country to expand its nuclear weapons programme.

Meeting South Korean President Yoon Suk Yeol in Seoul, Mr Guterres said he affirms the UN’s “clear commitment to the full, verifiable and irreversible denuclearisation of the Korean Peninsula and DPRK (Democratic People’s Republic of Korea).”

“There’s a fundamental objective to bring peace, security and stability to the whole region,” he told Mr Yoon, while also praising South Korea’s participation in international peacekeeping efforts and fighting climate change.

Mr Guterres, who arrived in South Korea on Thursday, later met South Korean Foreign Minster Park Jin for discussions that were expected to be centred around the North Korean nuclear threat.

North Korea has test-fired more than 30 ballistic missiles this year, including its first flights of intercontinental ballistic missiles since 2017, as leader Kim Jong Un pushes to advance his nuclear arsenal in the face of what North Korea has called “gangster-like” US-led pressure and sanctions.

The US and South Korean governments have also said the North is gearing up to conduct its first nuclear test since September 2017, when it claimed to have detonated a nuclear warhead designed for its ballistic missiles.

While the Biden administration has said it would push for additional sanctions if North Korea conducts another nuclear test, the prospects for meaningful punitive measures are unclear.

China and Russia recently vetoed US-sponsored resolutions at the UN Security Council that would have increased sanctions on the North over some of its ballistic missile testing this year, underscoring division between the council’s permanent members that has deepened over Russia’s war on Ukraine.

Mr Guterres’ meetings with South Korean officials came a day after North Korea claimed a widely disputed victory over Covid-19 but also blamed rival South Korea for the outbreak, vowing “deadly” retaliation.

The North insists its initial infections were caused by leaflets and other objects flown across the border on balloons launched by South Korea’s anti-Pyongyang activists, a claim Seoul describes as unscientific and “ridiculous”.