“Iran has pursued a longstanding effort to buy banned components for its nuclear and missile programs in recent months, a U.S. official said, a period when it struck an interim deal with major powers to limit its disputed atomic activity. Vann Van Diepen, principal deputy assistant secretary of state for international security and non-proliferation, added that a Chinese businessman indicted in the United States in 2009 over sales of missile parts to Iran continued to supply such items despite U.S. pressure on China to tighten export controls.”
Source: Iran seeks banned nuclear items, uses China trader for missile parts: U.S. | Reuters