US President Donald Trump has threatened to impose tariffs on an additional $200bn (£151bn) of Chinese goods in a growing trade row.
Mr Trump said the 10% tariffs would come into effect if China “refuses to change its practices”.
The threats would be a major escalation of the dispute and sparked further falls on stock markets.
China responded by accusing the US of “blackmail”, raising fears of a full-blown trade war.
Its commerce ministry said the country would take “qualitative” and “quantitative” measures and “fight back firmly” against additional tariff measures by the US government.
Mr Trump insists that China has been unfairly benefiting from a trade imbalance with the US for years.