VIENNA -- The United States and its Western allies have persuaded Russia and China to support a resolution critical of Iran's nuclear defiance in hope of showing Israel that diplomacy is an alternative to military force in pressuring Tehran, diplomats said Wednesday.

The resolution, which demands that Iran stop activities that could be used to make nuclear arms, cannot be enforced by the 35-nation board of the International Atomic Energy Agency, even if approved by vote or consensus as expected Thursday. But with Israel increasingly floating force as an alternative to failed international efforts to curtail suspected Iranian nuclear activities, the document is significant in seeking to show world-power resolve in pursuing a diplomatic solution to the standoff.

Israel views a nuclear-armed Iran as a mortal threat, citing Iran's persistent calls for the destruction of the Jewish state, its development of missiles capable of striking Israel, and Iranian support for Arab militant groups.

Tehran insists its nuclear program is for peaceful purposes only. But it refuses foreign offers of reactor fuel if it stops making its own through uranium enrichment - a process that worries the international community because it could also be used to arm nuclear warheads.

Concerns also focus on IAEA suspicions that Iran has worked secretly on nuclear arms - allegations Iran dismisses as based on fabricated U.S. and Israeli intelligence.

With fears growing over the possibility of Israeli military attack and other diplomatic efforts on Iran deadlocked, diplomats told The Associated Press that a resolution supported by the six powers seeking to engage Tehran on its nuclear program had become a priority discussed at the highest level.

The text was agreed on only after consultations involving U.S. Secretary of State Hillary Clinton and her counterparts in Russia, China, Britain, France and Germany, said the diplomats, who demanded anonymity because the negotiating process was confidential.

While the four Western powers had no differences, it was unclear until Wednesday whether Russia and China - which Iran has relied on to blunt harsh U.N. and other sanctions - would agree to join in backing the resolution. The diplomats said that they were persuaded largely with the argument that a signal of big-power unity had to be sent to Israel.

A Russian diplomat refused on Wednesday to discuss how the accord about the resolution came about.

Russia and China have been inconsistent in backing such Western efforts in the past. While joining in a critical resolution at an IAEA meeting in November, they refused to do so in June.

That unity came at a price for the West, however, which had to settle for compromise language in the current text, made available to The AP outside the closed meeting.

While expressing "serious concern" over continued Iranian uranium enrichment in defiance of the U.N. Security Council, the six nations say they back the "inalienable right" of countries that have signed the Nuclear Nonproliferation Treaty to develop nuclear energy for peaceful purposes. That is a bow to arguments by Iran, an NPT signatory that it has a right to enrich.

The resolution "stresses" that the IAEA has not reported any nuclear material missing from Iran sites it is monitoring. Missing material could mean that Tehran is using it elsewhere for weapons purposes.

It only "notes" that the agency cannot conclude there is no hidden nuclear activity going on because of "lack of cooperation" by Iran on agency requests that it be given greater powers to monitor the country.

Washington considers any signal to Israel that diplomacy is working crucial amid signs of increased jitters by the Jewish state about Tehran's nuclear progress.

Most recently, Israel Prime Minister Benjamin Netanyahu criticized what he said was the world's failure to spell out what would provoke a U.S.-led military strike against Iranian nuclear facilities. The comments came in response to U.S. refusals in recent days to set "red lines" for Tehran.

Israeli officials say American politics do not factor into their thinking, but that the sense of urgency is so grave that the world cannot hold its breath until after the U.S. presidential election in November.

"The world tells Israel, 'Wait. There's still time,'" Netanyahu said Tuesday. "And I say: 'Wait for what? Wait until when?' Those in the international community who refuse to put red lines before Iran don't have a moral right to place a red light before Israel."

Also Tuesday, diplomats told The Associated Press that the U.N. atomic agency has received new and significant intelligence over the past month that Iran has advanced its work on calculating the destructive power of an atomic warhead through a series of computer models within the past three years.

The diplomats who spoke to the AP said the information came from Israel, the United States and at least two other Western countries. They demanded anonymity because they were not authorized to discuss classified information member countries make available to the IAEA.