There are certain conditions which the US government does not allow. These pertain to a spouse, fiancee or applicant who has either overstayed in the US before, has HIV/AIDS or other contraventions of the US immigration laws.
You will not obtain a US visa if any of the following is applicable to you at the date of application or during the application process:
- The US Embassy during the interview suspects that you are not telling the truth;
- You have overstayed in the US before;
- You have HIV/AIDS;
- You have not received vaccination against vaccine-preventable diseases;
- You have a disorder that may pose a threat to the safety of yourself or others;
- You are a a drug abuser or addict;
- You have committed a crime;
- You are coming to the US principally, or incidentally to engage in prostitution;
- You are affiliated with the Communist or any other totalitarian party;
- You are planning to commit crimes in the US.
There is an entire list of conditions however these are what would possibly apply to you, your spouse or fiancee. To see the full list visit the following website.