UNITED NATIONS (XINHUA) - A spokesman for China's Permanent Mission to the United Nations (UN) has accused the United States of staging a "political show" by beginning to activate a snapback mechanism to restore UN sanctions against Iran.

"The US demand has no legal ground and common sense. It is nothing but a political show staged by the United States. It receives no support of the Security Council members and no acknowledgement of the international community," said the spokesman.

The spokesman was commenting on US Secretary of State Mike Pompeo's demand for the initiation of the snapback mechanism against Iran by the UN Security Council (UNSC).

Mr Pompeo also said that the US would sanction Russia and China if the two countries disregard the US demand for reimposing UN sanctions on Iran.

"The Joint Comprehensive Plan of Action (JCPOA), endorsed by UNSC Resolution 2231, has the force of international law," said the spokesman.

"In May 2018, the United States unilaterally withdrew from the JCPOA and reinstated illegal unilateral sanctions against Iran. This violated the JCPOA and UNSC Resolution 2231."

The spokesman added: "Having quit the JCPOA, the United States is no longer a participant to the JCPOA and has no right to demand the Security Council invoke a snapback as stipulated in Resolution 2231.

"In the meantime, a snapback mechanism should never be invoked until all efforts are made to exhaust dispute resolution process specified in the JCPOA. Therefore, the JCPOA participants and overwhelming majority of the Security Council members believe that the US demand has no legal basis, and a snapback mechanism has not been invoked."

The spokesman said that China's Permanent Representative to the UN Zhang Jun has sent a letter to the UNSC president to express China's opposition to the US demand.

"China will work with relevant parties to continue to uphold the just position, resolutely preserve the JCPOA and UNSC resolution, safeguard multilateralism, the authority of the Security Council, the international non-proliferation regime and regional peace and stability, and seek a political and diplomatic solution to the Iranian nuclear issue," the spokesman said.

"At the same time, we are firmly against US unilateral sanctions and 'long-arm jurisdiction' against other countries in the name of the Iranian nuclear issue, and will continue to safeguard our legitimate rights and interests," the spokesman added.