"Currently... 791 Chinese nationals have been relocated from Iran to safe areas," foreign ministry spokesman Guo Jiakun said at a regular news conference.

"More than 1,000 other people are in the process of relocating and withdrawing," Guo added.

And some Chinese nationals have also safely evacuated from Israel, he said.

"China expresses its thanks to the relevant countries for providing full support and assistance," Guo said.

Iran said early Wednesday it fired hypersonic missiles at Israel in the latest round of overnight strikes between the archfoes, hours after Donald Trump demanded the Islamic republic's "unconditional surrender".

The US president insists Washington has played no part in ally Israel's bombing campaign, but also warned Iran his patience is wearing thin as the conflict enters a sixth day.

World powers have pushed to find an off-ramp, hoping to prevent the conflict from spiralling into a region-engulfing war.

Trump fuelled speculation about American intervention when he made a hasty exit from the G7 summit in Canada, where the leaders of the club of wealthy democracies jointly called for a "de-escalation" of the conflict.

Back in Washington on Tuesday, Trump demanded the Islamic republic's "unconditional surrender".

He also boasted that the United States could easily assassinate Iran's supreme leader.

"Further escalation of tensions in the Middle East is not in the interests of any side," Guo said on Wednesday.

And in a thinly veiled reference to the United States, he said "countries that have a particular influence on Israel should especially uphold an objective and fair position, assume their due responsibilities and play a positive and constructive role in easing the situation".