VIENNA, Austria – Iran will no longer cooperate with the International Atomic Energy Agency in its investigation of allegations that its government has tried to make nuclear arms, Iran's vice president said Thursday.

Investigating such allegations “is outside the domain of the agency,” Vice President Gholam Reza Aghazadeh told reporters. Any further queries on the issue “will be dealt with in another way,” he added, without going into detail.

Aghazadeh also shrugged off a demand from six world powers to show flexibility on suspending uranium enrichment or face further U.N sanctions, and said Iran expected to be able to meet in the middle with its interlocutors.

The vice president, who also is head of Iran's Atomic Energy Organization, spoke after meeting with IAEA chief Mohamed ElBaradei and five days after Iran and the six powers ended Geneva talks still deadlocked on international demands that Tehran give up uranium enrichment.

Besides demanding a stop to enrichment – which can create both nuclear fuel and the fissile payload of warheads – the international community also has been pressuring Tehran to cooperate with the IAEA in its probe of allegations that Tehran hid attempts to make nuclear arms.

Since beginning its investigation last year, the IAEA has asked Iran in vain for substantive explanations for what seem to be draft plans to refit missiles with nuclear warheads; explosives tests that could be used to develop a nuclear detonator; military and civilian nuclear links; and a drawing showing how to mold uranium metal into the shape of warheads.

The United States and other Western nations accuse Iran of seeking to acquire nuclear weapons and demand that it freeze its uranium enrichment program. Iran says the program is for peaceful purposes. Iranian President Mahmoud Ahmadinejad on Wednesday again vowed Iran will not “retreat one iota” from pursuing it.

Talks in Geneva on Saturday had raised expectations for a compromise under which Iran would temporarily agree to stop expanding its enrichment activities. In exchange, the six world powers – the U.S., Germany, Britain, France, Russia and China – would hold off on adopting new U.N. sanctions against Iran. But participants at Geneva said Iranian negotiators skirted the enrichment freeze issue.

Secretary of State Condoleezza Rice said Monday that Iran had given the run-around to the envoys, while all six nations were serious about a two-week deadline for Iran to agree to freeze suspect activities and start negotiations or else be hit with new penalties.

But Aghazadeh said, “Both sides are carefully studying the concerns and expectations of both sides.” He added: “I am very hopeful” that the diverging standpoints will merge, allowing the start of substantial negotiations.