Top Chinese trade envoy Liu He was greeted Thursday by senior US officials as they resumed efforts to resolve their nations' escalating trade war.
The atmosphere surrounding the talks was acrimonious and shifting rapidly, with one news report overnight saying Chinese officials could cut short their visit.
Markets have pinned hopes on reports Chinese officials plan to avert fresh tariff increases by striking a partial bargain that falls short of addressing all of Washington's grievances.
But adding to the strains, Beijing again denounced Washington's sanctions on the telecommunications giant Huawei.
"I want to stress once again that the US practices are neither honorable nor ethical," foreign ministry spokesman Geng Shuang told reporters. "They are also a denial of the market economy principles that the US is always flaunting."
Earlier in the week, Washington fired a policy salvo at Beijing, slapping visa restrictions on senior officials and blacklisting dozens of companies accused of persecuting ethnic Muslims in the Xinjiang region.
The measures have outraged Beijing and in the process penalized major Chinese players in the artificial intelligence sector, in which both nations are intense rivals.
The South China Morning Post reported Thursday that preliminary trade talks in Washington among lower-level officials had not proved fruitful and the Chinese side was considering an early exit.
In the meantime, President Donald Trump faces a gathering political storm, amid the efforts by Democrats in Congress to impeach him and criticism from his own camp after pulling US forces from northern Syria and exposing allied Kurdish forces to a Turkish assault.
Data show with increasing clarity that the trade war is harming both economies, adding to pressure on the sides to strike a bargain.
Overnight, Wall Street futures bounced around erratically on competing news narratives for the hope of a positive outcome in the talks.