Providing proof of domicile in the United States is critical for most people when submitting Form I864, Affidavit of Support. Instead, submit a photocopy of these documents to NVC.However, you must bring these original documents to your visa interview. If you want to sponsor someone for a family-based green card, you need to provide proof of a U.S. domicile in your Affidavit of Support (Form I-864). I am currently living in the United States but they are requesting proof of US domicile but they're requesting proof of US domicile. U.S. citizens and green card holders sponsoring family members must present proof of domicile according to the National Visa Center (NVC). To complete Form I864, the petitioner must meet certain requirements. But what does "country of domicile" mean? You have to have three documents with you to enter the U.S. as an immigrant: your passport, your immigrant visa, and your medical report in a sealed envelope.