USAF, USN, USMC, and USCG require pilots to be officers, which means US military pilots are required to have a college degree. You don't necessarily need to be a US citizen, but you need to at least have a green card (be a full time legal resident). Citizenship would be a big plus. It takes 4 years to get a college degree and 5 years to become a naturalized citizen. So assuming you can get a residency visa, get into a college, earn a degree, and get accepted by and graduate from OCS (officer candidate school), you can then become a citizen while attending flight school. Good luck with all that. And I'm a naturalized US citizen and former USN pilot, so it can be done. But I started the process much younger.