Trump gave Tehran a 48-hour deadline on Saturday to end its partial blockade of the Strait of Hormuz, the narrow waterway into the Gulf through which about one-fifth of the world's oil flows, or risk an attack on its vital energy infrastructure.

The conflict and its impact on Hormuz has threatened global energy security as well as China's oil supplies and the "use of force will only lead to a vicious cycle", Chinese foreign ministry spokesman Lin Jian told a news conference, when asked about Trump's threats.

"If the war expands further and the situation deteriorates again, the entire region could be plunged into an uncontrollable situation," he said.

Beijing is a partner of Iran, which has been targeted by US-Israeli attacks since last month, but has also said it "does not go along" with Tehran's strikes against Gulf states housing US military bases and urged a ceasefire.

Trump, who was due to visit Beijing this month but delayed his trip to deal with the fallout from the war, had called on China and other countries to help reopen the Strait of Hormuz.

Beijing has yet to answer that call, but has sought to mediate in the Middle East, sending its special envoy Zhai Jun on a tour of the region to urge de-escalation.

Foreign minister Wang Yi said earlier this month that the war "should never have happened" and called for an end to fighting.