From this link:
https://admissions.usafa.edu/RRS/International_Booklet
also here:
International Programs
AUTHORITY: U. S. Air Force Academy enrollment of students from the American Republics and the Republic of the Philippines began in June 1962. Enrollment of students from other countries began in 1985, as authorized by the Secretary of the Air Force.
ELIGIBILITY: Each candidate must meet the following eligibility requirements:
1. Be unmarried, with no dependents, bonafide citizen of the nominating country, and be of good moral character. Meet high leadership, academic, physical, and medical standards.
2. Be not less than 17 years of age and must not be past their 23rd birthday by 1 July of the year in which they enter the Air Force Academy.
3. Be proficient in reading, writing, and speaking contemporary English.
4. Have an acceptable academic record.
5. Achieve qualifying scores on the College Board Scholastic Aptitude Test (SAT) or the American College Testing (ACT). SAT Math scores below 560 or ACT Math and Science Reasoning scores below 25 are not competitive.
6. Be in good health and free of any communicable disease. In addition, each nominee must have good vision and be free of major dental problems.
7. We will need to know the service commitment of the student once they graduate and return to their country.
NOMINATING METHODS: To apply for a nomination, applicants should write to their own country, NOT to the Academy or the United States government offices. An applicants letter should contain complete details about their background. The number of nominations authorized for each country will be provided by the Air Force Academy. Nominations from host governments are processed through the USDAO/American Embassy. These nominations are to be submitted to the Air Force Academy by 31 December for the class entering the following June. Governments should submit nominations to the American Ambassador as early as possible upon receipt of official nominations from the government to which they are accredited.