BEIJING (Reuters) - China said on Tuesday it hoped for a “clear” message to be sent with new UN sanctions on North Korea over its nuclear program, but would not comment on the draft, saying there had been too much speculation about the details.

The Security Council is set to vote on Wednesday to impose new sanctions on North Korea for its fifth and largest nuclear test, slashing Pyongyang’s export earnings by some $800 million, diplomats say.

Diplomats say the council’s five veto-wielding powers - the United States, China, Britain, Russia and France - have agreed to new measures, seen by Reuters on Friday, that largely target the hermit Asian state’s coal export earnings.

In Beijing, Chinese Foreign Ministry spokesman Geng Shuang said China supported further action against North Korea, but that it should be targeted and not harm normal humanitarian, civilian or development needs.

“At present the Security Council members are having consultations on the draft,” Geng told a daily news briefing.

“We hope Security Council members can reach consensus on the draft as soon as possible, to send a clear and united message.”

North Korea has been under U.N. sanctions since 2006 over its nuclear and missile tests. It conducted its latest nuclear test on Sept. 9, and the United States and China, North Korea’s most important diplomatic and economic backer, spent more than two months negotiating new sanctions.

China is believed to be the only country that now buys North Korean coal and under the U.S.-drafted U.N. resolution likely to be adopted it would cut its imports by some 60 percent, or $700 million on 2015 sales, diplomats said.

The new sanctions would cap North Korean coal exports at $400.9 million, or 7.5 million metric tonnes, annually, whichever is lower, starting on Jan. 1. Over the first 10 months of this year, China imported 18.6 million tonnes of coal from North Korea, up almost 13 percent from a year ago.

Coal is one of North Korea’s only sources of hard currency and its largest single export item. The draft U.N. resolution would also ban exports of copper, nickel, silver and zinc, which the U.S. official said are worth about $100 million a year.

Asked about the details of the new sanctions, Geng said there had been a lot of speculative reports around ahead of the resolution being passed.

“So it’s not appropriate to comment on conjecture and supposition.”

China has always been conscientious about enforcing UN resolutions, and all countries have an obligation to do so, he added.