Following decades of enmity and a prolonged shadow war, Israel launched a surprise aerial campaign last week against targets across Iran, saying it aimed to prevent its arch-foe from acquiring atomic weapons -- an ambition Tehran denies.

The sudden flare-up in hostilities has sparked fears of a wider conflict, with Trump urging Iran back to the negotiating table after Israel's attacks derailed ongoing nuclear talks.

Trump also issued an extraordinary warning on his Truth Social platform: "Everyone should immediately evacuate Tehran!"

Asked about Trump's remarks, Chinese foreign ministry spokesman Guo Jiakun said: "Fanning the flames, pouring oil, making threats and mounting pressure will not help to promote the de-escalation of the situation, but will only intensify and widen the conflict.

"The Chinese side calls on all relevant parties, especially countries with special influence on Israel, to shoulder their responsibilities, take immediate measures to de-escalate tensions, and prevent the conflict from expanding and spreading."

China's embassies in Iran and Israel also urged Chinese citizens to leave the countries "as soon as possible", after Israel and Iran traded heavy strikes.

"The Chinese Embassy in Iran has coordinated with the Iranian side to facilitate outbound travel and reminds Chinese citizens currently in Iran to leave the country... as soon as possible", the embassy in Tehran said in an online statement.

It suggested border crossings with Turkey, Armenia, and Turkmenistan as possible routes out.

China's embassy in Israel urged citizens to depart "in the direction of Jordan" as it warned that the conflict was "continuing to escalate".

"Much civilian infrastructure has been damaged, civilian casualties are on the rise, and the security situation is becoming more serious," it said in a post on WeChat.