Hi Praveen,
A little clarification please...
You were working as a Domestic Recruiter previously.
Now you are working as US Recruiter.
Both the experiences are (I believe from your post) into consultancy / staffing agency.
Your concern on IT firms having separate HR and Staffing team.
Usually these days, many companies have diversified their HR teams as -
Recruiting specialist
L&D Officer / Training specialist
Employee Engagement Team
Performance Appraisal Team
so on and so forth.
Now the main task of an HR is to hire the right talent.
The technicality is taken care of by the department heads, but sourcing the talent.
Many companies outsource this to staffing agency or have a dedicated recruitment team.
The other people on HR takes care of other things.
I hope this clarifies you to some extent on how HR department works these days.
About your wish to making a career in HR domain, can you be a little more specific as to where your interest lies as HR is full of different responsibilities.
Knowing your experience level, when it comes to recruitment, both your working experience will be counted.
For all other roles, you would be considered fresher.
I hope I have nearly answered your query.