A Defense Department report has identified Sudan as the second leading military client of China.
"China sells arms to Sudan despite the passage of UN Security Council resolutions 1556  and 1591 , both of which call for the prevention of the transfer of arms to Darfour," the report said.
"The PRC argues that arms sales constitute part of normal commercial relations, and that the arms supplied by Chinese companies were not meant for use in Darfour."
The report said Iran has also been a leading Middle East client of China.
Some of the Chinese weapons supplied to Iran were said to have been transferred to insurgency groups in Afghanistan and Iraq.