China on Thursday threatened retaliation if Washington steps up their war over trade and technology by going ahead with planned Sept. 1 tariff hikes on additional Chinese imports.

Beijing will take unspecified ``necessary countermeasures,'' the Cabinet said. It gave no details.

President Donald Trump has said he plans to impose 10% duties on an additional $300 billion of Chinese imports.

The Chinese announcement made no mention of Trump's decision Wednesday to postpone penalties on about 60% of those goods until December.

Their lopsided trade balance means China has almost run out of U.S. imports for tariff hikes following previous increases in retaliation for American punitive duties. But Beijing already has extended penalties for U.S. companies by delaying customs clearance for their goods and delaying issuing licenses in finance and other fields.