China's Foreign Ministry on Thursday said it will take "firm counter measures" if the United States continues to interfere in Hong Kong.
It said legislation signed by US President Donald Trump on Wednesday backing protesters in Hong Kong was a serious interference in Chinese affairs and US efforts were "doomed to fail".
It warned that the United States will shoulder the consequences of China's countermeasures if it continues to "act arbitrarily" in regards to Hong Kong.
The legislation signed by Trump was approved unanimously by the US Senate and by all but one lawmaker in the House of Representatives last week. The law also threatens sanctions for human rights violations.