China said on Tuesday that UN Security Council sanctions against Iran should not be wilfully elaborated or expanded.

Foreign Ministry spokesman Qin Gang made the remarks at a regular press briefing when commenting on U.S. sanctions recently imposed on Iran.

"China has noted that the United States and other parties have unilaterally imposed further sanctions on Iran," said Qin, referring to the new sanctions approved by U.S. President Barack Obama on July 1.

Described by Obama as the "toughest" ones ever passed by the Congress, the new sanctions penalize international firms linked to Iran's energy industry, Revolutionary Guards or nuclear programs.

"Not long ago, the U.N. Security Council approved resolution 1929. China believes that the Security Council resolution should be fully, seriously and correctly enforced," he said.

Saying that China will seriously enforce the resolution, the spokesman reaffirmed the importance of dialogue and negotiations for a comprehensive, long-term and proper solution of the Iran nuclear issue.

Qin said the relevant parties should continue to work for the resumption of talks.