A new international group committed to eliminating nuclear weapons over the next 25 years has enlisted scores of world leaders as its campaign gets under way at a conference in Paris on Tuesday. "The aim is to get to zero," said Richard Burt, chief strategic weapons negotiator for President George W. Bush. Even Iran is considered a potential supporter, he said in an interview. "If there is growing support by nuclear powers and public opinion worldwide, I think it becomes harder for any government, including Iran, to cross that barrier," Burt said. The group, Global Zero, is proposing deep cuts in US and Russian nuclear arsenals, a verification and enforcement system, and phased reduction leading to the elimination of all stockpiles. Listed supporters include former President Jimmy Carter; former Secretary of State Lawrence Eagleburger; former Defense Secretary Frank Carlucci; former Soviet leader Mikhail Gorbachev; Shaharyar Khan, a former Pakistani foreign minister; retired Air Chief Marshal Shashindra Pal Tyagi of India; and Malcolm Rifkind, a former British foreign secretary.