China has American agricultural exports in its cross hairs as it prepares countermeasures against fresh U.S. import tariffs, China's state-backed Global Times reported, raising the stakes in an escalating trade war between the world's top two economies.

Trump's call for an additional 10% levy on goods from China - which he said would also go into effect on Tuesday - had not been previously announced, though during his presidential campaign he backed border taxes on Chinese products of as much as 60%.

The U.S. next week will impose an additional 10% tariff on imports from China over its role in the fentanyl trade, the president said.