UNITED NATIONS, Sept. 20 (Xinhua) -- Zhang Jun, China's permanent representative to the United Nations, on Sunday wrote a letter to the president of the Security Council and UN secretary-general, expressing opposition to the U.S. unilateral announcement on the return of UN sanctions on Iran on Saturday.

In his letter, Zhang said that the United States unilaterally withdrew from the Joint Comprehensive Plan of Action (JCPOA) in May 2018, and is no longer a JCPOA participant. Therefore, it is illegitimate for the United States to demand the Security Council invoke the snapback mechanism.

In response to the U.S. letter dated Aug. 20, 13 members of the Security Council earlier wrote to the president of the Council and clearly stated that any decision or action resulting from the U.S. letter is devoid of any legal, political or practical effect. Their view was also reflected by the president in his conclusion on Aug. 25.

Zhang emphasized that given the above, the snapback mechanism shall not be deemed as invoked. The provisions of resolutions 1696 (2006), 1737 (2006), 1747 (2007), 1803 (2008), 1835 (2008) and 1929 (2010) will continue to be terminated pursuant to OP 7 (a) of Resolution 2231 after Sept. 20.

China is committed to upholding the efficacy of the JCPOA and the authority of the Security Council resolution, and will make relentless efforts toward the political solution of the Iranian nuclear issue, he stressed.