The US has ordered China to close its consulate in Houston, Texas, by Friday - a move described as "political provocation" by Beijing.
US Secretary of State Mike Pompeo said the decision was taken because China was "stealing" intellectual property.
China's foreign ministry condemned the move on Twitter, saying its embassy in Washington had received death threats.
Earlier, unidentified individuals were filmed burning paper in bins in the Houston building's courtyard.
Tensions have been rising between the US and China for some time. President Donald Trump's administration has clashed repeatedly with Beijing over trade and the coronavirus pandemic, as well as China's imposition of a controversial new security law on Hong Kong.
