By GEORGE JAHN
VIENNA (AP) - Senior U.N. investigators trying for more than a year to restart a probe into Iran's alleged work on nuclear arms chose their words carefully Tuesday about hopes for success as they left for Tehran on a trip that sets the stage for separate talks between six world powers and the Islamic Republic.
Iran insists it has never tried to develop nuclear arms - an assertion underlined by the Foreign Ministry in Tehran as the U.N. team of International Atomic Energy Agency experts prepared to board the flight bound for the Iranian capital.
Ministry spokesman Ramin Mehmanparast said a religious decree issued by Iran's supreme leader banning nuclear weapons is binding for the Iranian government, suggesting the edict should be enough to end the debate over whether Tehran is pursuing atomic arms.
"There is nothing higher than the exalted supreme leader's fatwa to define the framework for our activities in the nuclear field," he said. "When the highest jurist and authority in the country's leadership issues a fatwa, this will be binding for all of us to follow."