WASHINGTON, July 8 (Xinhua) -- The United States announced Tuesday to impose sanctions on four Iranian individuals and four entities for their ties to Iran's nuclear and missile programs.

　　The individuals include Dawood Agha-Jani, Moshen Hojati, Mehrdada Akhlaghi Ketabachi, and Naser Maleki, while the entities designated include Shahid Sattari Industries, Seventh of Tir, Ammunition and Metallurgy Industries Group, and Parchin Chemical Industries, according to a statement of the U.S. Treasury Department.

　　As a result, U.S. citizens will be prohibited from any transactions with them, and their assets under U.S. jurisdiction will be frozen.

　　"Iran's nuclear and missile firms hide behind an array of agents that transact business on their behalf," said Stuart Levey, the Treasury's under secretary for terrorism and financial intelligence.

　　"As long as Iran continues to engage in such deceptive practices, companies and banks must exercise extraordinary vigilance to avoid participating in illicit transactions," he said.

　　The United States has accused Iran of trying to develop nuclear weapons. Iran has denied the charges.