Washington and its allies need to take swift action to curb Iran\'s slow and steady march toward building a nuclear bomb, a Republican lawmaker said. A Tuesday report by the International Atomic Energy Agency said there are concerns that some aspects of Iran\'s nuclear program are tailored toward the development of a weapon. U.S. Rep. Ileana Ros-Lehtinen, R-Fla., chairwoman of the House Foreign Affairs Committee, said time is short for Western allies to take action against Iran as it moves closer to its perceived nuclear weapon ambitions. \"The IAEA report that Iran is developing a nuclear weapon is further proof that the U.S. and other responsible nations must take decisive action to stop the regime from acquiring a nuclear capability,\" Ros-Lehtinen said in a statement. Iran, in a 117-page response to the U.N. nuclear watchdog\'s claims, said much of the concerns are related to outdated developments in the Iranian nuclear program. \"If the Iranian regime acquires nuclear weapons capabilities, the U.S., Israel, and our other allies in the region and around the world will face an unimaginable threat to our security,\" said the congresswoman, a harsh critic of U.S. funding for some U.N. programs. \"The clock is ticking.\" Iran in September started operations at its Bushehr nuclear plant with the help of Moscow.