US entry for previous citizen?

[raichu059]

My brother was born in the US but left when he was 3. He had a US passport but never returned & has been living in Australia. He turned 21 and didn’t renounce his passport - he is now 25 & wants to come into the US https://100001.onl/ https://1921681254.mx/ .

Will he be able to? He also never filed tax returns in the US for his Australian income/ trading… so there’s that.

Any advice for what he should do?