In this case, you must prove this to us by showing your current US immigration documents
How do I get a Social Security card if I am a J-1 student, student intern or an international visitor?
For this example, you will be required to provide a letter from your sponsor. This letter will need to be on a letterhead, with the original signature of your sponsor which authorizes your employment
Can I use a Social Security number that has been assigned to me for non-work purposes to work?