Advance Parole!!! If you don't want to go, but your firm pressures you to, get Advance Parole and move where ever they want you to. But, do maintain an address in the US (change of address submission to the INS service center, state department) and have the paystub go to that address. Then, when you get your approval, avail a leave of couple of weeks, come to US using the Advance Parole, get your approval and then if you care to leave the company, do so.
Many will caution you on not leaving the company soon after getting the GC, so take care of that too.
-Palaniappan Rajaram