Sources told the South China Morning Post that officials in Beijing had grown bolder since playing its rare earths card in October and were now less worried about tariffs.
The sources, who spoke on condition of anonymity because they were not authorised to comment publicly, said Chinese officials believed Beijing had the ability to retaliate strongly and to withstand the pressure if Washington escalated.
That confidence could offer some clues as to how Beijing will approach the summit between President Xi Jinping and Trump.
In October, the two countries agreed to a trade truce that involved Washington easing certain tariffs and China resuming soybean imports and suspending some rare earth export curbs.