If an immigrant is currently waiting for their Petition for Alien Relative, otherwise known as Form I-130, to be approved, then it is possible for them to live within the U.S. with their spouse and children until the petition has been reviewed. According to U.S. Citizenship and Immigration Services, a K-3 or K-4 visa is available as a means for petitioners and their children to obtain nonimmigrant residency while they wait.
A K-4 visa can be applied for by any underage and unmarried children of an immigrant who has a K-3 visa, or immigrants who are qualified to apply for a K-3 visa. If an immigrant is the spouse of a U.S. citizen, has filed their Form I-130 and is waiting for a verdict, then he or she is considered qualified to apply for a K-3 visa.