U.N. watchdog chief seeks nuclear clarity in Iran

By Mark Heinrich

VIENNA (Reuters) - The U.N. nuclear watchdog chief headed for Iran on Thursday to push for full transparency over its past and present atomic activity after U.S.-Iranian tensions were heightened by a naval incident in the Gulf.

Keen to resolve Iran's standoff with the West over its nuclear ambitions without conflict, International Atomic Energy Agency Director Mohamed ElBaradei may try to capitalise on signs of improving Iranian cooperation with IAEA investigators.

A diplomat close to the IAEA said on Tuesday their inquiries, which Iran stonewalled for years until August, had entered a final phase with Tehran addressing U.S. intelligence about past, covert attempts to "weaponise" atomic material.

In talks with Iranian leaders on Friday and Saturday, ElBaradei hopes to "develop ways and means to enhance and accelerate" steps to clarify the past and current scope of Iran's nuclear efforts, an IAEA statement said.

An Iranian official said ElBaradei, who declined to speak to reporters at Vienna airport before leaving, will meet President Mahmoud Ahmadinejad and Foreign Minister Manouchehr Mottaki.

He was expected to seek an end to curbs on U.N. inspections, key to verifying Iran's denials of any diversions of nuclear materials into bomb-making, as well as press for a rapid conclusion of the investigation into Iran's past.

His trip coincides with a Middle East tour by U.S. President George W. Bush aimed at garnering Arab support to rein in Iran. Bush called Iran "a threat to world peace" on Wednesday, three days after Washington said Iranian boats harried U.S. naval forces in the Gulf.

Iran said its craft asked U.S. ships to identify themselves and accused Washington of trying to stir up tension.