How can I bring my nine year old nephew to the US if his mother died?

You would have to try to adopt him and once he is legally declared to be your child, then you can bring him to the US.

He may qualify as an orphan or by adoption. Adoptions are nowadays very complicated depending on the country of birth. You must consult with an experienced immigration attorney before you do anything else.

The first issue is whether you are a U.S. citizen. For purposes of this answer I will assume you are a U.S. citizen. If your nephew is a legitimate orphan you can bring him to the U.S. on an orphan petition. In the alternative, you could adopt your nephew and bring him to the U.S. through the adoption process. That said, you must first legally adopt him and he must live in your legal and physical custody for two (2) years before he can immigrate to the U.S. Your nephew cannot simply enter the country on a tourist visa and spend two (2) years in your custody in order to fulfill the two (2) year requirement as he must demonstrate nonimmigrant intent to enter on a tourist visa. If you adopt your nephew and he enters on a tourist visa this indicates an intent to immigrate. Possible alternative options include attempting to obtain humanitarian parole to enter the U.S. or going to your nephew's country, filing for legal physical custody and living with him in his native country for two (2) years before he can come to the U.S. Contact an immigration attorney for assistance.

You can make efforts to adopt him. However, it is no easy process and there is a two year legal custody requirement.

You may be able to adopt him as an orphan or get him a status Special Juvenile Immigrant. Both options have very detailed requirements to qualify. You need to speak to an immigration attorney directly.

You would have to legally adopt him.