I can only offer perspective on working in the US.
Most overseas workers come into the US on an H1-B visa that is good for 3 years. There are limited number available each year, and these slots get filled up almost instantaneously by larger companies hiring technical talent from abroad. This requires the sponsorship of a US company, which means you would need to have a job offer before you can apply for one.
Part of the H1-B process looks at your education and experience - the employer must justify why they are hiring a non-US worker for the position. Thus you are in a better position the more skills and schooling you have.
HR is a challenging field for this because it requires knowledge of the local laws and regulations, something difficult for a non-US applicant to acquire. My guess is having experience at a global organization, where you might leverage that experience in a similarly global
HR team in the US, would be one of the few possibilities.
There are other visa options as well, but they require somewhat unique circumstances (a student status, a spouse working in the US under a visa, etc.). This is too lengthy to get into here. My suggestion is to at least finish your degree - that should be a minimum requirement for the work visa. Then you may want to focus on developing a more specialized or unique
HR skill set (applicable globally) that would attract a US company's attention.