Unless it's a Canadian license, you have to complete the ATP-CTP, pass the written and pass a checkride. Holding a foreign ATP only lets you skip getting the FAA commercial which is normally a requirement to get the ATP. And to get a FAA commercial you have to hold a FAA private (different rules for military pilots.) The only certificate the FAA will issue based on a foreign license without a checkride is a private. The foreign license verification is to prove you hold a foreign license to skip the commercial.