Beijing has warned of strong countermeasures if United States President Donald Trump signs a Hong Kong rights Bill into law.

The Hong Kong Human Rights and Democracy Act was passed unanimously by the US Senate on Tuesday evening. It was approved by the House of Representatives earlier. If signed into law, the Bill allows for diplomatic and economic sanctions if Washington deems Beijing to have crossed the line in eroding Hong Kong's autonomy.

China condemned the Bill as a move to interfere in its internal affairs and its Vice-Foreign Minister Ma Zhaoxu yesterday summoned a US envoy to lodge a "strong protest".

Various Chinese organs - including the top legislature, the Hong Kong and Macau Affairs Office of China's Cabinet - added to the chorus of condemnation.