Key member states plan in the coming weeks to elect a new leader of the UN agency charged with probing Iran's nuclear program, pressing Syria to reveal its atomic secrets and thwarting terrorists from getting the bomb. The two men vying for the post of director general of the International Atomic Energy Agency are a study in contrasts. One, a low-key Japanese career diplomat, would be expected to depoliticize the agency. The other, a South African former anti-apartheid activist, promises a more hands-on approach to mediating nuclear crises. The vote by the IAEA's 35-nation board will therefore have significant repercussions for how the agency deals with the nuclear weapons and safety challenges confronting the world. Whether the winner is Japan's Yukiya Amano or South Africa's Abdul Samad Minty there is consensus that he will have large shoes to fill. Mohamed ElBaradei's 12-year tenure as IAEA chief will be remembered as a time when the agency rose from relative obscurity to playing pivotal roles in investigating first Iraq, then Iran for possible nuclear weapons programs. North Korea left the agency and developed a nuclear bomb during the ElBaradei years and Syria came under suspicion after Israel jets bombed what the U.S. said was a reactor built secretly and meant to produce plutonium when completed. ElBaradei himself grew from an unobtrusive civil servant into a Nobel Peace Prize winner with a penchant for outspokenness that critics say exceeded his role as impartial head of a U.N. agency tasked with purely technical duties. Washington unsuccessfully lobbied in 2005 to block his appointment to another four-year term because his statements on Iran and Iraq were peppered with barely disguised criticisms of U.S. policy. With the vote on a successor possible as soon as early March, Amano is telling IAEA delegations that he is close to the two-thirds majority needed to succeed ElBaradei, whose third term ends in November, said diplomats, who demanded anonymity in exchange for divulging confidential information. But with no clear date set on a vote, Minty could press undecided countries for support in the days ahead, leaving Amano short of the margin of victory needed when balloting does take place. That in turn could give Minty extra time to garner more backing - or lead to the nomination of a compromise candidate. The change in leadership comes at a potentially pivotal time in U.S.-Iran relations: after decades of cold-shouldering Iran, the new American administration has signaled it is ready for direct negotiations with Tehran over nuclear and other issues. Washington is known to prefer Amano as the less political candidate, but was not showing its cards ahead of the vote. "We look forward to timely consideration of the candidates," said Susan Doman, spokeswoman to the U.S. mission to the IAEA. "The U.S. will not disclose its position in a secret ballot election." Both Amano and Minty are the chief IAEA delegates of their countries and wield other formidable credentials, including senior national nonproliferation posts as well as chairmanships of IAEA and other nuclear meetings. And both say they see the IAEA's role as essentially a technical organization that follows the direction of the 35-nation board. But Minty, a one-time disarmament campaigner as well as anti-apartheid activist, suggests he would play an active mediating role in key nuclear issues. "My life philosophy ... is to bring consensus, to work with a team approach," he told The Associated Press, when asked if he saw himself as a bridge-builder on Iran and other matters dividing the IAEA board. "If countries want to build consensus on these issues, it's possible because of my background." His views as South Africa's chief IAEA delegate have occasionally put him at odds with the U.S. and its allies on Iran and other issues, something Minty acknowledged may work against him. "If the big countries decided they need to have control ... they would not consider me," he said. Japan, in contrast is solidly in the Western camp on Iran and other issues. And Amano does not believe the IAEA head should get involved in the daily fray. As potential IAEA head he said: "I don't see myself as a mediator" but more as the executor of policies set by the board. His nationality and approach have given Amano key backing from Western countries seeking a change from the outspoken ElBaradei. The vote could come in early March when the board meets in regular session: a restricted copy of the agenda shared with the AP lists "Appointment of the Director General" as an item. And if meeting chairwoman Taous Feroukhi of Algeria delays the secret ballot - as Western diplomats say she might do - the pro-Amano camp might still call for a "straw vote" - nonbinding but meant demonstrate Amano's lead and help him when a later, formal ballot is held.