China has openly supplied Iran with nuclear materials and was a major economic partner to the nation from 1985 to 1997, when pressure from the Clinton administration hampered the business. Last month, the White House announced sanctions against Bank of Kunlun, part of the state-owned China National Petroleum Corp, saying that the bank had "facilitated transactions worth millions of dollars on behalf of Iranian banks." (Read more: .) "The Chinese business community has not shown any sign that they accept US sanctions against Iran," said John Moscow, a New York lawyer who investigated international bank fraud and money laundering with the Manhattan district attorney's office from 1988 to 2004. Law enforcement officials worry that Chinese banks "will attempt to structure their legal affairs so that they can do business with America and Iran, which means keeping secrets from the U.S.," Mr. Moscow said.