To work in the US as an SLP as a non-resident, the following steps are required for you to pursue employment:
1. Obtain American Speech-Language Hearing Association certification, this is the national organization for SLPs in the US. Documentation of your education will be required, as well as evidence of your experience as an SLP. This may also involve passing the NESPA, a Praxis examination. Once all documentation is submitted, there is a waiting period. Details here.
2. Once ASHA certification is obtained, then you would apply for licensure in the state where to desire to work. Once all documentation is submitted, there is a waiting period. Details here.
3. Once ASHA certification has been obtained and you have received documentation of state licensure, you are ready to apply for a job as an SLP in the US.
4. Seek out companies that are willing to sponsor your visa. You can utilize the Nice Speech Lady Open SLP Positions page or on other forums and state clearly from the start that you require visa sponsorship for hiring. The company that hires you will need to walk you through the visa application process.
Good luck on your journey, friend.