UN atomic watchdog chief Mohamed ElBaradei urged Iran yesterday to "unblock" its nuclear standoff and expressed hope that a possible change in US policy towards Tehran would break the deadlock.

"I again urge Iran to implement all measures required to build confidence in the exclusively peaceful nature of its nuclear programme at the earliest possible date and to unblock this stalemated situation," ElBaradei said in his opening speech to the International Atomic Energy Agency's 35- member board of governors here.

And he added: "1 am hopeful that the apparent fresh approach by the international community to dialogue with Iran will give new impetus to the efforts to resolve this longstanding issue."

The Egyptian-born diplomat did notspecifi-cally mention the United States, but he was clearly referring to the signal from new President Barack Obama that he is ready to talk with Iran directly to resolve the standoff.

Even after a sLx-year investigation, the IAEA has been unable to say once and for all whether Iran's controversial nuclear programme is entirely peaceful, asTehran claims.

In the watchdog's latest report on the mat-

ter, ElBaradei complained that Iran was stonewalling on key questions regarding the possible military dimension of past nuclear work and also defying UN orders to suspend uranium enrichment, a process that can be used not only to make nuclear fuel, but also the fissile material for a bomb.

Referring to IAEA's investigation into allegations of illicit nuclear work by Syria, ElBaradei pressed Damascus to come clean on a suspect site in the remote desert, which the US alleges had been an undeclared nuclear reactor until it was bombed by Israeli planes in September 2007.

"The agency expects Syria to provide additional information and supporting documentation about the past use and nature of the buildingat the Dair Alzour site," ElBaradei said.

Syria must also provide access to additional related sites, the IAEA chief said.

"Such access, together with the sampling of the destroyed and salvaged equipment and debris, is essential for the agency to complete its assessment," he said.

Earlier Iran on Monday reiterated its denial that it is seeking to make a nuclear bomb, after top US military commander Admiral Mike Mullen alleged that Tehran has enough fissile material to build such a weapon.