Whether you're a birthright citizen or were naturalized, you can petition to bring your foreign-born fiancé(e) to the United States for the wedding. They can use a K-1 visa, as long as you intend to marry within 90 days of their entry. Once you are married, your spouse can apply for lawful permanent residence (green card status) and, eventually, citizenship.
Are you a highly skilled or educated person who wants to study or work in the United States?
If you are a U.S. citizen or lawful permanent resident (green card holder), your spouse may be eligible to join you in the U.S. and become a lawful permanent resident right away. This applies to both new and longer-term spouses from abroad.
The U.S. Citizenship and Immigration Services recently announced a significant policy change. In the past, when an application for a visa or lawful permanent resident status contained errors, the USCIS adjudicator would issue a Request for Evidence (RFE) or a Notice of Intent to Deny (NOID). This would notify the applicant of a deficiency in their application and give them a chance to address the problem before the application was officially denied.
If you had been married for less than two years when you were granted permanent residence (a green card), your status is conditional. The reason is that you are required to prove your marriage was legitimate and not a so-called "green card marriage" meant to thwart U.S. immigration law.
While previous administrations focused on deporting only those immigrants who commit serious crimes, the Trump administration has made clear that anyone in the United States without proper authorization is fair game for deportation. Furthermore, immigration agents will arrest unauthorized immigrants wherever it finds them.