UNITED NATIONS • The UN Security Council has unanimously imposed its toughest sanctions on North Korea, placing a cap on the hermit state's key coal exports after its defiant nuclear tests.

The new sanctions resolution was passed by a 15-0 vote. It was spearheaded by the United States and came after three months of tough negotiations with fellow veto-wielding council member China.

The resolution demands that North Korea "abandon all nuclear weapons and existing nuclear programmes" and takes aim at the state's exports of coal, its top external revenue source. Under Resolution 2321, North Korea will be restricted from exporting more than 7.5 million tonnes of coal next year, a 62 per cent reduction from 2015.

North Korea's Foreign Ministry said yesterday it rejects the latest sanctions, saying they denied its sovereignty and right to survival.

It said in a statement that the country will be taking stronger self-defence measures in response, the country's KCNA state news agency said.

Ms Samantha Power, the US Ambassador to the United Nations, said the resolution would strip the regime of more than US$700 million (S$999.8 million) in hard currency, dramatically reducing the money it can spend on weapons.

Speaking to reporters with her counterparts from South Korea and Japan, she said the move marked "the strongest sanctions regime the Security Council has imposed on any country in more than a generation".

UN Secretary-General Ban Ki Moon urged all countries to enforce the resolution. "It sends an unequivocal message that the DPRK must cease further provocative actions and comply fully with its international obligations," he said.

AGENCE FRANCE-PRESSE, REUTERS