The row between China and Japan has ratcheted up a notch, with Beijing issuing a strongly worded position paper warning that Tokyo would soon be able to produce nuclear weapons.In the document released on Thursday, China called on the United Nations to make Japan’s potential pursuit of nuclear arms an “important agenda item” at an ongoing convention at the organisation’s New York headquarters. China is a permanent member of the UN Security Council and will assume the monthly rotating presidency of the body in May.

In the report, the Chinese foreign ministry warned that Tokyo had mastered the ability to extract weapons-grade plutonium and had the necessary reprocessing technologies and facilities.

“Japan has long produced and stockpiled plutonium materials far exceeding the actual needs of its civilian nuclear energy programme, giving it the capability to achieve a ‘nuclear breakout’ within a short period,” the document said, according to state news agency Xinhua.

“Allowing right-wing forces in Japan to push for the development of powerful offensive weapons, or even the possession of nuclear weapons, would inevitably once again bring harm to the international community and have seriously negative impacts on international peace, security and stability.”

Plutonium-239 is a primary fissile isotope used for the production of nuclear weapons, along with uranium-235.