The Bush administration said Monday Iran was making headway in developing nuclear weapons, and Secretary of State Condoleezza Rice tried to iron out differences with her Russian counterpart on a resolution designed to stop the program with economic sanctions. While not predicting when Iran would join the nuclear club, State Department spokesman Sean McCormack said the Iranians were trying to perfect centrifuge technology and the operation of centrifuges. "It's a very tricky matter of perfecting centrifuge technology so you can actually enrich all the uranium," McCormack said. "So, yes, they are going along their way in trying to go down the various pathways." The spokesman provided no details of Rice's telephone conversation with Russian Foreign Minister Sergey Lavrov. "They went over some of the outstanding issues," McCormack said.