I am not aware of any limit to how much money he can bring to the U.S., but he may wish to have the money wired to a U.S. account if he is concerned about travelling with too much cash. There is a limit to funds a person takes out of the U.S., and perhaps his country also has rules about how much money a person can remove.
The above is intended only as general information, and does not constitute legal advice. You must speak with an attorney to discuss your individual case.
When entering the US, you have to declare $10,000 or more, whether in dollars, foreign currency, or other monetary instruments.
[This answer is for general purposes only; it does not constitute advice and does not establish an attorney-client relationship.]
You have to declare any funds being brought into the U.S. if the funds aggregate $10,000 or more. However, you can always send money electronically to avoid having to declare it. However, he may wish to consider doing some pre-immigration tax planning before he enters the U.S. and becomes a permanent resident. There may be certain benefits available to him as a foreign national that he wants to capitalize on before becoming a permanent resident.
If you have additional questions, he should speak to an immigration lawyer, whether myself or one of my colleagues. If you appreciate the time spent preparing this answer, kindly consider marking it BEST ANSWER or HELPFUL. Good luck to you.
Dean P. Murray
The Murray Law Firm
560 Sylvan Avenue
Englewood Cliffs, NJ 07632
Mr. Murray's response is NOT legal advice and does NOT create an attorney-client relationship. You should NOT rely on this response. Mr. Murray's response was generated without conducting a full inquiry as would occur during a face to face attorney-client consultation. It is likely that the response above may be made less accurate, or become entirely inaccurate, as you, i.e. the questioner, disclose additional facts that should only be discussed during a private consultation with an attorney. I strongly recommend that you consult an attorney who is licensed to practice law in your state (or, in the case of immigration law, and attorney in ANY state), whereupon all relevant facts will be discussed. All responses posted by Mr. Murray on Avvo.com are intended as general information for the education of the public, and not for any specific individual.