美国称伊朗宣布核技术进展言过其实

The United States has downplayed Iran's claims of advances in its nuclear program, saying Tehran is feeling the pressure of international sanctions and wants to distract from its growing diplomatic isolation. Iran said Wednesday it had installed a new generation of centrifuges to enrich uranium, and for the first time loaded domestically produced nuclear fuel into Tehran's research reactor. U.S. State Department spokeswoman Victoria Nuland dismissed the announcements as "hype." Israel and Western powers suspect Iran is trying to speed up enrichment of uranium to the higher purity to develop nuclear weapons. Iran says its enrichment activities are aimed at producing fuel for power plants and medical research. Nuland says Iran must show its nuclear program is for civilian purposes.
 
Iran hailed the advances as a step toward mastering the complete nuclear fuel cycle, despite U.N. and Western sanctions aimed at stopping the process. White House spokesman Jay Carney said Iran is making "defiant" statements because its leadership and economy are under "enormous pressure" from sanctions. Israel and its chief ally the United States refuse to rule out military action to prevent Iran from building a nuclear weapon. Israel sees an Iranian atomic bomb as a threat to its existence.