SHARM EL-SHEIK, Egypt -- U.S. Secretary of State Hillary Rodham Clinton expressed doubt Monday that Iran would respond to the Obama administration's diplomatic initiatives toward Tehran on nuclear and other issues, a senior State Department official said.

Clinton made the statement in a private meeting with the foreign minister of the United Arab Emirates, Abdullah bin Zayed Al Nahyan, who had expressed to Clinton a concern among Persian Gulf nations that Obama might make a deal with Iran without full consultation with U.S. allies. The official who described the exchange spoke on condition of anonymity because the meeting was private.

Clinton told her counterpart that the Obama administration is carefully calculating its moves and will consult fully with Gulf allies.

"We're under no illusions," the official quoted Clinton as telling al Nahyan. "Our eyes are wide open on Iran."

Clinton and Abdullah were in Sharm el-Sheik to attend an international conference to raise money for the war-torn Gaza Strip. They met during a break.

She told the UAE minister, whose country has close historic commercial ties to Iran but is wary of Iranian nuclear ambitions, that she doubts the Iranian government will respond to U.S. diplomatic initiatives. Last week Clinton announced that she has appointed veteran diplomat Dennis Ross to be her special adviser on matters related to the Gulf, to include overtures to the Iranians.

The U.S. official said Clinton's statement did not reflect a change in her view of the likely outcome of efforts to engage Iran. The Bush administration refused to deal with Iran unless it first halted its uranium enrichment program, which Iran insists is strictly for peaceful nuclear energy but that the United States and other countries believe is a step toward building an arsenal of nuclear weapons.

On Sunday in Washington, Adm. Mike Mullen, chairman of the U.S. Joint Chiefs of Staff, said in a broadcast interview that Iran has sufficient fissile material for a nuclear weapon and warned of a dire outcome if Tehran moves forward with building a bomb.

The International Atomic Energy Agency said Iran has processed 2,222 pounds (1,010 kilograms) of low-enriched uranium. But the report left unclear whether Iran is now capable, even if it wanted, of further enriching that material to the much higher degree needed to build a warhead.

On Monday, Iranian Foreign Ministry spokesman Hasan Qashqavi told reporters in Tehran, "We have said many times that a nuclear weapon has no place in Iran's defense doctrine."

Obama has said from the start of his administration that if Iran unclenched its fist the United States would extended an open hand.

Clinton also told her UAE counterpart that Iran's "worst nightmare" is an international community united against Iranian nuclear ambitions, the U.S. official said.

Clinton made clear from the start of the Obama administration that Iran is one of her highest priorities, and that diplomatic success is not assured.

"We will pursue a new, perhaps different approach that will become a cornerstone of what the Obama administration believes is an attitude toward engagement that might bear fruit," Clinton said at her Senate confirmation hearing in January. "We have no illusions, Mr. Chairman, that even with a new administration, looking to try to engage Iran in a way that might influence its behavior, that we can predict the results."