In a major blow to Iran’s economy, China has sharply cut its purchases of Iranian oil, ahead of comprehensive US sanctions from November 5.

The Chinese Government instructed two large State oil companies, China National Petroleum Corp. and Sinopec, to avoid any purchases. “People with knowledge of the matter” said the ban is temporary, as Beijing seeks a waiver from the American sanctions.

The US measures were ordered by Donald Trump in May, as he withdrew from the 2015 nuclear agreement between Iran and the 5+1 Powers (US, UK, France, China, Russia, and Germany). Any foreign company which continues business with Tehran is threatened with a cut-off from the American financial system.

China is already facing a trade war launched by Donald Trump, with tariffs imposed on half of Beijing’s exports to the US and the warning of duties on the other half.

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Spokesmen for both CNPC and Sinopec declined to comment. Foreign Ministry spokeswoman Hua Chunying said at a briefing on Wednesday, “The Chinese side welcomes a practical solution that can maintain normal economic and trade cooperation with Iran.”

Chinese leader Xi Jinping and Trump are scheduled to meet at next month’s Group of 20 summit.

Beijing is by far the largest customer for Iran, which has lost 40% of its exports since April as other countries have reduced purchases. The biggest refiners in India, Tehran’s second-largest customer, have drawn down imports although Delhi is continuing some purchases as it hopes for a US waiver.

Iran Appeals to US to Accept ICJ Ruling

With less than two weeks before the imposition of the full US sanctions, which include the energy and financial sector, Iran is stepping up its international campaign calling for resistance.

Iran’s ambassador to the UN told the General Assembly on Thursday that Washington must abide by an order issued by the International Court of Justice earlier this month, criticizing the sanctions for humanitarian effects such as restrictions of medicines and food and risks to civil aviation.

Gholamali Khoshroo called on the US “to implement the provisional measure, including refraining from measures such as wrongful sanctions which will aggravate the disputes”.

He asked other states to refrain from assisting the US in imposition of any restrictions on transactions involving specified items.