China hosts summit with Russia, Iran as nuclear deal wobbles

Iran, China and Russia may seek ways to salvage the nuclear deal ditched by Donald Trump when their leaders meet this weekend at a summit on the Chinese coast.

The Shanghai Cooperation Organisation (SCO), a regional security bloc led by China and Russia, is set to hold its 18th annual gathering in the city of Qingdao on Saturday and Sunday.

Iran's President Hassan Rouhani is attending this year -- just the second time an Iranian leader has participated.

It comes after US President Trump controversially pulled Washington out of a 2015 international pact with Iran that placed limits on its nuclear programme in return for easing economic sanctions.

China is Iran's top trade partner and one of the biggest buyers of its oil, but those who oppose the US abandonment of the deal risk huge fines for busting the tough American measures.

Rouhani is taking part because "Iran is currently evaluating the signatories of the nuclear deal to see to what extent they'll be able to effectively maintain it even after the US's withdrawal", said Gao Shangtao, an expert on Middle East relations at Beijing Foreign Affairs College.

"To put it bluntly, if Tehran feels assured that China and Russia can withstand the pressure of US sanctions and continue to do business with Iran, then Tehran will seek to retain the deal -- otherwise, it's meaningless," he said.

Chinese businesses are expected to step up activities in Iran to fill the void left by the exit of US companies and the possible withdrawal of European rivals who fear punitive US measures.

Hua Liming, a former Chinese ambassador to Iran, told the Global Times newspaper on Tuesday: "Unlike the US, China will not break its promise and will ensure that China-Iran relations won't be affected."