Last year it was given full membership of the Shanghai Co-operation Organisation, a Eurasian security and economic club dominated by China and Russia. In January Iran was admitted to BRICS, another group that China and Russia are trying to nurture as a bastion of West-sceptics.

Iran exports nearly half of its oil production and uses the rest for its own domestic needs. The sliver of Iran’s oil exports that China does not purchase is shipped mainly as economic assistance or barter to two nearly bankrupt allies, Syria and Venezuela, that have little money to pay for fuel.

Oil futures tumbled Tuesday, with the U.S. benchmark dipping back below $70 a barrel, after a report that Israel will not attack key oil facilities in Iran. The Washington Post, citing officials familiar with the matter,