The United States has voiced its support for a European plan that would give Iran more time to negotiate with the European Union about its suspect nuclear program. But top U.S. diplomat Gregory Schulte told the International Atomic Energy Agency Thursday that it should not have unlimited patience with Tehran over its non-compliance with the Nuclear Non-Proliferation Treaty. He said Iran's cooperation with the IAEA has so far been disappointing. Mr. Schulte spoke in Vienna, at a meeting where the 35-nation IAEA board was expected to approve a U.S.-backed E.U. draft proposal for new talks with Iran. Those talks are set to focus on a Russian plan to process Iranian nuclear fuel in IAEA member-country Russia, rather than in the Islamic republic. The United States and Europe accuse Iran of clandestine efforts to develop an atomic bomb. Tehran insists its program is aimed at developing electricity.