For the past year the US government have (strongly) spoken out against the influence of the Chinese Communist Party on Hong Kong, and have made into law the Human Rights and Democracy Act which allows sanctions to be imposed on officials who do not respect human rights in HK.
Contrarily, the UK government have been less enthusiastic on this issue as only a few warnings/voices of concern such as that by the Foreign Secretary have been issued. Although some MPs have suggested a similar Act (i.e. Magnitsky) in the UK, it has not been passed to date.
Given that Hong Kong was a British colony for 150 years, I find it surprising that the British government have done less than the US government in terms of monitoring/assessing HK's situation. Or to turn it the other way round, why have the US government done more despite that historically the US-HK relationship was much weaker than the British-HK relationship?