“Everyone knows that 40 percent of the oil shipped daily to every part of the world goes through the Strait of Hormuz, so once war starts in this region not only will the relevant nations be affected and attacked, it would also … bring disaster to a world economy deep in crisis,” Chen Xiaodong warned on Tuesday.

The director general for the Chinese Foreign Ministry’s Department of West Asian and North African Affairs was referring to the Iranian threat to prevent the transit of oil shipments through the strategic waterway if attacked.

“We urge all relevant nations to remain calm, exercise restraint, refrain from taking actions that will intensify the situation and make common efforts to prevent war,” Chen said.

On Monday, IAEA Spokeswoman Gill Tudor said the agency confirms that “Iran has started the production of uranium enriched up to 20%” at the Fordo facility.

She added that “all nuclear material in the facility remains under the agency’s containment and surveillance”.

Following the IAEA statement, US State Department spokeswoman Victoria Nuland claimed that Iran’s enriching uranium to 20 percent at the Fordo site was “a further escalation of their ongoing violations with regard to their nuclear obligations.”

Iran’s ambassador to the IAEA responded by saying all of the country’s nuclear activities, including those at Fordo enrichment site, are under the supervision of the UN atomic body.

“This site [Fordo] was declared more than two years ago and since then the agency is continuously monitoring… all the activities,” Ali Asghar Soltanieh said on Monday.

The US and its allies accuse Iran of pursuing a military nuclear program and have pressured the UN Security Council to impose four rounds of sanctions against the country.

As a signatory to the Nuclear Non-Proliferation Treaty and a member of the International Atomic Energy Agency, Tehran insists it is entitled to utilize nuclear energy for peaceful purposes.