The ICAO does not issue pilots licences, only national or supranational aviation licensing authorities can do that. Most countries are accredited members of ICAO including the United states. It would be as well to decide where you are likely to be able to work and seek to aquire that countries licence either by training to that standard, or obtaining the necessary conversion requirements.
ICAO state that :
ICAO does not issue any licences. Licences issued by ICAO Contracting States on the basis of Standards and Recommended Practices of Annex 1 – Personnel Licensing, are habitually called ICAO licences. This has led many to believe that there is a specific ICAO or international licence. The fact is that there is not one single international licence issued by ICAO or any other organization. States issue their own licences based on national regulations in conformity with Annex 1 specifications and validate licences issued by other Contracting States on the basis of bilateral or multilateral agreements or the fulfilment of nationally legislated requirements.