VIENNA (Reuters) -- The United States and five other big powers have said they were committed to direct talks with Iran to defuse a standoff over its disputed nuclear work, underlining a U.S. turnabout from a policy of confrontation.
Speaking at a UN nuclear watchdog meeting, the six voiced "serious concern" at Iran's atomic advances and increasing restrictions on UN inspectors trying to keep track of them, but did not mention toughening sanctions as a way to rein in Iran.
"We remain firmly committed to a comprehensive diplomatic solution, including through direct dialogue," the United States, Britain, France, Germany, Russia, and China said in a statement to the International Atomic Energy Agency's board of governors.
"[We] urge Iran to take this opportunity for engagement with us and thereby maximize opportunities for a negotiated way forward," France's IAEA governor, Olivier Caron, speaking on behalf of the six, told the 35-nation gathering in Vienna.
In a switch from predecessor George W. Bush's strategy of isolating rather than talking to U.S. foes, U.S. President Barack Obama has said he would be open to engaging with Iran on a range of issues, from its nuclear ambitions to how it could help bring peace to Afghanistan.
Iran has reacted cautiously, saying it is open to fair talks while demanding fundamental changes in U.S. policy, by which it means U.S.-driven sanctions, accusations Iran actively seeks nuclear weapons and supports terrorism.
U.S. Secretary of State Hillary Clinton told an Arab foreign minister on Monday she was "doubtful" Iran would respond to U.S. outreach once made and had "no illusion" about success.
Obama has made no concrete offer yet of talks, pending the outcome of a sweeping foreign policy review due in a few weeks.
And his administration has re-floated the option of seeking harsher international sanctions on Tehran, if it does not open up to IAEA investigations and shelve sensitive nuclear activity of possible use in producing atom bombs.
A fresh U.S. commitment under Obama to multilateral cooperation to solve frozen conflicts has cheered many at the IAEA, raising hopes of coaxing Iranian cooperation and easing fear of war shattering non-proliferation efforts.
The six-power group omitted mention of sanctions, common in statements by Western members at earlier IAEA meetings, to preserve unity -- Russia and China oppose further punitive steps -- and underscore a direct diplomatic approach critically undermined by Washington's pointed absence under Bush.
But they stressed Iran had to reciprocate by suspending enrichment and giving inspectors documentation and on-the-ground access to resolve allegations of secret military dimensions to Iran's nuclear fuel program.
Iran, they said, must also grant wider-ranging inspections beyond declared nuclear sites to allay mistrust in its goals.
Iran says it is enriching uranium for a planned network of nuclear power plants, not weapons as Western powers suspect.
The United States cut off all relations with Iran in 1980 after militants took U.S. diplomats and officials hostage.
The United States, addressing the IAEA governors on its own on March 1, held out the prospect of "direct engagement" with Iran, Syria, and North Korea to help the IAEA tackle suspected proliferation challenges posed by the three nations.
U.S. Ambassador Gregory Schulte cited "a moment of unparalleled opportunity with a renewed American commitment to the United Nations and multilateral diplomacy."