New US sanctions imposed on elements of Iran's Revolutionary Guard Corps reflect the Obama administration's strategy of punishing the elite corps and not the Iranian people over the country's nuclear and missile programs.The Treasury Department said Wednesday it was freezing the assets in US jurisdictions of Revolutionary Guard Gen. Rostam Qasemi and four subsidiaries of a previously penalized construction firm he runs because of their alleged involvement in producing and spreading weapons of mass destruction.On Thursday, Iranian President Mahmoud Ahmadinejad claimed Iran had produced its first batch of enriched uranium enriched to a higher level. The United States and some of its allies accuse Teheran of using its civilian nuclear program as a cover to build nuclear weapons, but Teheran has denied the charge, saying the program is just geared toward generating electricity.The US sanctions expand existing unilateral penalties against elements of the Guard Corps, or IRGC, which Western intelligence officials believe is spearheading Iran's nuclear program. While the sanctions are aimed at changing the government's behavior, it will be difficult to gauge their effect as it is not clear what holdings the targets may have in US jurisdictions.The administration is pushing to internationalize such penalties so they will have greater impact, and the announcement came as US officials lobby for similar action at the UN Security Council, which has already hit Iran with three sets of sanctions over Teheran's failure to prove its nuclear program is peaceful.Qasemi commands the Guard Corps' Khatam alAnbiya Construction Headquarters, which Treasury described as its engineering arm, which is involved in the construction of streets, tunnels, waterworks, agricultural projects and pipelines. Its profits "are available to support the full range of the IRGC's illicit activities, including WMD proliferation and support for terrorism," Treasury said in a statement.Khatam alAnbiya was hit with US sanctions by the Bush administration in 2007. Wednesday's penalties apply to Qasemi and Khatam al-Anbiya subsidiaries, the Fater Engineering Institute, the Imensazen Consultant Engineers Institute, the Makin Institute and the Rahab Institute. "As the IRGC consolidates control over broad swaths of the Iranian economy, displacing ordinary Iranian businessmen in favor of a select group of insiders, it is hiding behind companies like Khatam al-Anbiya and its affiliates to maintain vital ties to the outside world," said Stuart Levey, Treasury undersecretary for terrorism and financial intelligence.Treasury's move followed a tough new warning to Iran from US President Barack Obama, who said on Tuesday that the country remains on an "unacceptable" path to nuclear weapons, despite its denials, and that the US and like-minded countries would soon present a set of punishing sanctions at the United Nations.His comments came in response to Iran's announcement that it wasrejecting a deal it provisionally accepted in October under which itwould ship low-enriched uranium to Russia for further enriching for usein a Tehran medical research reactor. On Sunday, Iran said it wouldproduce its own higher-enriched uranium. On Tuesday, Iranian statetelevision said the process began in the presence of inspectors fromthe UN's nuclear watchdog, and Ahmadinejad claimed success Thursday.