Britain, France and the United States planned to spend much of Wednesday in talks with each other and Russia and China, going back over proposals for a council statement. They could circulate a new text late in the day.
The decision to cancel the council discussion on Tuesday reflected the failure of the US and its European allies to get Russia and China on board during a meeting of high-level diplomats in New York the night before.
One council diplomat described that meeting as a setback for British, French and American efforts to craft a tough council response to Iran, which the West believes is seeking nuclear weapons.
Russia and China say any Security Council action should be mild.
"We're trying to get back on track from where we were before last night's meetings," said the diplomat, who spoke on condition of anonymity because the talks were confidential. "The Russians and the Chinese came in guns ablazing."
US, European pressure
The United States and its European allies want the Security Council to approve a statement reiterating demands by the UN nuclear watchdog, the International Atomic Energy Agency, that Iran suspend uranium enrichment.
"We're trying to get back on track from where we were before last night's meetings. [But] the Russians and the Chinese came in guns ablazing"
Iran says it is not enriching uranium to make a nuclear bomb, but the United States disputes this.
Diplomats said the Russians and Chinese have not budged from their opposition to tough language including a demand for a report in 14 days on Iran's compliance with the IAEA demands.
Moscow and Beijing have said that is not enough time, with China suggesting 30 to 45 days.
Council diplomats including John Bolton, the US ambassador, had hoped for council action on Tuesday. But Britain and France decided to reopen talks on a council statement and put off a meeting of all 15 council members.
Jean-Marc de La Sabliere, France's UN ambassador said: "France's opinion is that this message must be strong and precise. We still hope that we can reach an agreement."
Iran says it is producing nuclear
power for civilian use only
Russia and China also want the IAEA to keep the main role in cajoling Iran on uranium enrichment. They have raised concerns that pushing Iran too hard could lead to its withdrawal from the Nuclear Non-proliferation Treaty and expulsion of IAEA inspectors.
Wang Guangya, China's ambassador to the UN, said on Tuesday: "From the beginning I proposed that if the Security Council is to support IAEA, it is to have a brief political statement and support the IAEA."
Nicholas Burns, the US undersecretary of state, told reporters on Tuesday that he was convinced the council could come to agreement on action, probably in the form of a non-binding Security Council statement.
"I think we will see a statement not too long in the future," Burns said in Washington.
Monday's meeting had been intended to discuss broad strategy on Iran as well as a first council response. Britain has proposed offering Iran a package of unspecified incentives as a way of getting Russia and China to agree to the threat of tougher council measures later.
Russia's Putin and China's Hu are
reluctant to get tough on Iran
But all sides made little headway, emerging only to express concern that Iran has not met IAEA demands.
The lack of significant movement after 10 days could lead the Western nations to abandon the presidential statement, which requires the consensus of all 15 council members, in favour of a resolution, a council diplomat said on condition of anonymity.
That would put Russia and China in the position of having to approve, abstain or veto action against Iran.