BEIJING: China called on Monday for all countries to make constructive efforts to ease tension after North Korea said the latest UN sanctions against it are an act of war and tantamount to a complete economic blockade.

The UN Security Council unanimously imposed new sanctions on North Korea on Friday for its recent intercontinental ballistic missile test, seeking to limit its access to refined petroleum products and crude oil and its earnings from workers abroad.

The US-drafted resolution also caps crude oil supplies to North Korea at 4 million barrels a year and commits the Council to further reductions if it were to conduct another nuclear test or launch another intercontinental ballistic missile (ICBM).

North Korea on Sunday rejected the resolution, calling it an act of war.

Speaking in Beijing, Chinese Foreign Ministry spokeswoman Hua Chunying said the resolution appropriately strengthened the sanctions but was not designed to affect ordinary people, normal economic exchanges and cooperation, or humanitarian aid.

Hua noted it also called for the use of peaceful means to resolve the issue and that all sides should take steps to reduce tension.

"In the present situation, we call on all countries to exercise restraint and make proactive and constructive efforts to ease the tensions on the peninsula and appropriately resolve the issue," she told a daily news briefing.

The North's old allies China and Russia both supported the latest UN sanctions.

Tension has been rising over North Korea's nuclear and missile programmes, which it pursues in defiance of years of UN Security Council resolutions, with bellicose rhetoric coming from both Pyongyang and the White House.

In November, North Korea demanded a halt to what it called "brutal sanctions", saying a round imposed after its sixth and most powerful nuclear test on September 3 constituted genocide.

North Korea on Nov. 29 said it successfully tested a new ICBM that put the US mainland within range of its nuclear weapons.

US diplomats have made clear they are seeking a diplomatic solution but proposed the new, tougher sanctions resolution to ratchet up pressure on North Korea's leader.

China, with which North Korea does some 90 percent of its trade, has repeatedly called for calm and restraint from all sides and for a return to talks.