"Unilateralism is on the rise. Rejection of international law, not just lack of respect for international law but in fact contempt for international law, is on the rise and we need to work together," Zarif said.
Zarif made a five-hour visit Sunday to the seaside resort of Biarritz, where he met with French President Emmanuel Macron and French, German and British diplomats.
He said he planned to brief Wang on "the latest developments as well as my tour of Europe and my discussions in Biarritz with our French colleagues" in the nuclear agreement.
Wang said in his opening remarks that "unilateralism is rising and power politics is emerging."
"Facing this situation, China as a responsible country agrees to work with Iran and other countries to work together for multilateralism, the basic rules of international politics and uphold the rightful interests of each country," Wang said.
Zarif's visit to Beijing comes amid heightened tensions between China and the U.S. over their spiraling trade dispute and unrest in Hong Kong that Beijing accuses Washington of encouraging or even directing.