China's chief negotiator on North Korea's nuclear program says Beijing remains opposed to unilateral sanctions against the Pyongyang regime taken without the approval of the U.N. Security Council.

The Foreign Ministry said Wu Dawei also told his South Korean counterpart in talks Friday that China was "adamantly opposed" to the South's deployment of an advanced U.S. missile defense system that China says poses a threat to its own security.

Wu also pressed for a resumption of six-nation talks on the North's nuclear programs that have been stalled since North Korea walked away from them in 2009. The talks involved North and South Korea, China, the U.S., Japan and Russia.