BEIJING (AP) – The U.S. nuclear envoy said Thursday that Washington was likely to give Chinese diplomatic efforts over North Korea’s nuclear and missile programs only a few more days before pushing for a tough U.N. resolution.

“My sense is we’re down to a number of days,” U.S. Assistant Secretary of State Christopher Hill told reporters in Beijing.

His comments came as Japan pressed for a vote on its resolution threatening sanctions for the North’s missiles tests last week, while China and Russia introduced a rival proposal, intensifying jockeying over a unified response.

Backers of the Japanese-sponsored resolution had agreed to postpone a vote to give Beijing time to lobby Pyongyang to return to six-party nuclear disarmament talks and declare a moratorium on missile tests. But North Korea appears to have rejected diplomatic overtures by a Chinese delegation, including nuclear negotiator Wu Dawei, that is visiting Pyongyang.

“So far they don’t seem to be interested in listening, much less doing anything to address the situation,” Hill said at a separate briefing.

China’s U.N. ambassador, Wang Guangya, said the delegation, which will return Friday, delivered a message from China’s leaders expressing concern over the tests “and also what we considered the North Koreans should do to make diplomacy succeed.”

But Wang said they had not received any feedback.

“The Chinese are as baffled as we are,” Hill said. They “sent a good delegation up to Pyongyang, showed a real interest in trying to work with the DPRK _ but it does not appear to have been reciprocated,” he said, using the initials for the North’s official name, the Democratic People’s Republic of Korea.

Japan demanded a prompt U.N. vote on its proposal for sanctions and possible military action.

“There is no change to our view that the resolution incorporating sanctions should be voted on promptly,” Chief Cabinet Shinzo Abe said in Tokyo, without giving a deadline. “We cannot be pushed around by intentions to diminish or delay” action against North Korea.

China, a permanent U.N. Security Council member, threatened to veto the Japanese resolution, which is supported by the United States, Britain and France.

On Wednesday, China and Russia introduced a rival resolution at the United Nations in New York that “strongly deplores” the missile launches and calls on Pyongyang to re-establish a moratorium on testing but drops mandatory sanctions, military action and the determination that the launches threatened international peace and security.

Hill said it was natural for there to be “a lot of last-minute pushing and shoving, a lot of last-minute ideas” before a vote. He said he remained confident that “there will be a very strong, very clear message to North Korea.”

Pyongyang ignited the furor July 5 by test-firing seven missiles, including a long-range Taepodong-2 potentially capable of hitting the United States. The weapons, which landed in the ocean between the Korean Peninsula and Japan, triggered fresh worries over regional security.

Japan’s Yomiuri newspaper reported that Tokyo was concerned that two of the missiles fired by North Korea may have been newly developed long-range Scuds that can reach Japan.

Japan has suggested it may consider pre-emptive strikes on North Korean missile bases, which are permissible under Japan’s pacifist constitution. But Tokyo appears to have backed away from the possibility in face of criticism from its neighbors.

In the South Korean port city of Busan, high-level talks between the two Koreas ended Thursday a day ahead of schedule, after the North renewed a demand for food aid of 500,000 tons of rice but refused to address the missile issue.

Seoul urged the communist state during the talks to resolve the missile crisis and return to nuclear talks, but Pyongyang showed no sign of complying. Instead, the North blamed South Korea for the collapse of the talks, claiming Seoul had raised issues unrelated to the forum.

“While repeating what others say, the South side created an artificial obstacle to the talks, without discerning where military threat to the Korean Peninsula come from,” the North’s delegation said after the talks ended.

“North-South high-level talks are never military talks or six-party talks,” the delegation said, referring to the six-nation talks aimed at curbing the country’s nuclear aspirations.