ASTANA, May 18, 2018 (News Wires) - Russia and China moved Thursday to extend their economic influence in Iran, while Europeans are finding it harder to ignore US efforts to isolate Tehran economically. In one of the most concrete moves yet against renewed U.S. efforts to choke off Iran economically, a Russian-led trade bloc signed an interim trade deal with Iran and signaled plans to negotiate a free trade zone. Meanwhile, Iran's oil minister said that Chinese state-owned oil company CNPC was ready to replace Total on a major gas field project in Iran if the French energy giant pulls out. The fate of Total's participation in the gas project demonstrates the difficulty the European Union faces in resisting Washington's move as European firms stand to lose much more from busting US sanctions. Earlier this month US President Donald Trump controversially pulled Washington out of an international deal with Iran that placed limits on its nuclear program in return for easing economic sanctions. China, Russia and European Union members Britain, France and Germany were also signatories of the 2015 pact and opposed Washington's abandonment of the deal that Iran had respected. But companies around the world now face a tough choice as Washington has previously slapped huge fines on firms that bust U.S. sanctions. This week the EU launched work on a plan to keep the nuclear deal alive and French President Emmanuel Macron said Thursday that one reason is "so that our businesses can remain" in Iran. However Total has indicated it will go forward with the investment only if it wins an exemption from Washington on the sanctions. Other European firms are likely to make a similar calculation that the U.S. market is worth much more to them than Iran. Danish shipping giant Maersk Tankers said Thursday it would cease its activities in Iran, while German insurer Allianz has also announced it plans to wind down its business deals there. Meanwhile Russia, one of the strongest defenders of the Iran nuclear deal, tightened its trade ties with Tehran. In the Kazakh capital Astana, the Russia-led Eurasian Economic Union trade bloc signed an interim trade deal with Iran that lowers tariffs on hundreds of goods. The bloc, which also comprises Armenia, Belarus, Kazakhstan and Kyrgyzstan, also plans to begin three years of talks with Iran that aim to create a free trade zone.