China says a U.S. decision to deny its Bank of Kunlun access to the U.S. financial system violates international norms. It said the U.S. step was taken because the bank has been accused of providing financial services to banks in Iran. Foreign Ministry spokesman Qin Gang said in a statement the sanction on the Chinese bank seriously violates international norms and China will raise solemn representations to the United States, the China Daily reported. Qin said China and Iran enjoy normal relations and open business cooperation, and China has no connection to Iran\'s nuclear program. \"China has been consistent and clear regarding its position on non-proliferation. It firmly maintains the principles of the international non-proliferation system and commits itself with parties involved, including the U.S., to solving the Iranian nuclear issue,\" the spokesman said. \"But the United States has ignored China\'s concerns and repeatedly imposes sanctions against Chinese enterprises and banks. This will negatively affect Sino-U.S. bilateral cooperation.\" China Daily said the Bank of Kunlun belongs to China National Petroleum Corp., and its main clients include large state-owned enterprises, companies and staff members in the energy and petrochemical industries.