WASHINGTON, Jan. 12 (Xinhua) -- The United States on Monday imposed sanctions on 13 people and three private companies involved in nuclear proliferation led by Pakistani scientist Abdul Qadeer Khan.

    "We believe these sanctions will help prevent future proliferation-related activities by these private entities, provide a warning to other would-be proliferators, and demonstrate our ongoing commitment to using all available tools to address proliferation-related activities," the State Department said in a statement.

    The statement also called for international vigilance "to ensure that Khan network associates, or others seeking to pursue similar proliferation activities, will not become a future source for sensitive nuclear information or equipment."

    The 13 people subject to the U.S. sanctions include British, German, Turkish, Swiss and Sri Lankan nationals. Under U.S. laws, any bank accounts or other financial assets found in the United States that belong to them must be frozen. Americans also are prohibited from doing business with them.

    Khan, who is revered in Pakistan as the father of Pakistan's atomic weapons program, confessed in 2004 to playing a major role in the international nuclear smuggling ring.