✔ 最佳答案
I do not know anything about UK and Australia.
In the US, you need to be a greencard holder or US citizen to work unless
there is an US company willing to sponsor you.
Typically US employment agencies do not do the sponsorship for you.
In most cases, HK employees get promoted and transferred to the US office that
the companies sponsor the HK employees.
In my company, an agency, Manpower Inc. introduced a foreign temp worker from Chad, Africa to us. He said the agency had him to show his green card before they talk.
The agency did not charge him a fee. Rather the agency charges my company a fee.
Wish you the best of luck!