By Evelyn Leopold

UNITED NATIONS (Reuters) - The United States and its allies on Friday predicted adoption of a U.N. Security Council statement on Iran's nuclear ambitions next week, although China and Russia still had misgivings.

U.S. Ambassador John Bolton told reporters after a closed meeting of the 15-nation council that a Franco-British draft statement "is certainly very close to agreement."

Both Russia and China have been apprehensive that council involvement would take the issue away from the Vienna-based International Atomic Energy Agency. They also fear that Security Council action would escalate and lead to possible sanctions or other punitive measures.

One sticking point was a demand for a report from the head of the Vienna-based International Atomic Energy Agency within 14 days. But Bolton and the British and French ambassadors said the council could be flexible and extend the reporting time. China had proposed four to six weeks.

"We have signaled that there is flexibility, on the assumption we adopt this text soon," French Ambassador Jean-Marc de la Sabliere said. "But the longer it takes, then the shorter the time will be."

Another problem was whether the report from the IAEA should go to the council or the nuclear watchdog's 35-member governing board first. British Ambassador Emyr Jones Parry said both would receive it simultaneously, although the statement only mentions the Security Council.

"The council should not be fettered in its consideration of that report by any consideration elsewhere," he said. "But that report should also be available to the agency and to its governing board. So it is simultaneity."

"We are now very close to the end of the discussions," de la Sabliere said. He hoped for adoption on Tuesday but that Russia and China still needed instructions from their respective governments.

China's U.N. ambassador Wang Guangya said Russia and China still had differences with the draft that expresses "serious concern" about Iran's nuclear program and asks the IAEA to report on whether Tehran had complied with its demands. It does not threaten sanctions.

But Bolton said, "I think they can clearly see that the rest of the council, with some possible additional modifications, basically, in broad substance, is ready to go".

The draft statement also calls on Iran to suspend uranium-enrichment efforts, which the West believes are a cover for bomb-making. Iran insists its research is intended to produce nuclear energy, but the IAEA is concerned Tehran might be seeking atomic weapons.

China's Wang told the meeting the draft statement should be shorter and not spell out each demand, even its main points duplicated those from the IAEA governing board, participants at the session reported.

To reporters, Wang said, "We need to send a message ... that the Security Council is supporting, reinforcing the role of the IAEA, not replace it or take it over from IAEA."

But Bolton said, "The urgency of sending a clear and strong signal to Iran is certainly very much on our mind, conscious as we are that the Iranian centrifuges are spinning with uranium hexafluoride in them. That is a very serious matter."

He was also asked about comments from Russia's U.N. Ambassador Andrei Denisov that the pace of council action was too fast. "If I were as near to Iran as Russia is I would certainly want to get this resolved quickly," Bolton said.

The 15 council members meet again on Tuesday, a day after senior foreign ministry officials, including U.S. Undersecretary of State Nicholas Burns, come to meet in New York to discuss future strategy. The other officials are from Britain, France, Russia, China and Germany.