If you have issued a K-1 visa, congratulations, this is a milestone in the immigration process, but the journey is not over yet. After receiving the K-Visa, the Consular Officer will return to you your passport, now stamped with the K-1 visa. You will also be given a sealed packet with the supporting documentation that you previously gave to the consulate, in addition to other forms generated by the U.S. Embassy or Consulate. Under no circumstances should you open the packet. Only the DHS officer may unseal the packet after you seek physical admission to the United States.
Now that you have your K-visa, you make seek admission once only at U.S. port of entry within six month after receiving the visa. Very important though, you only have 90 days to marry your fiance after entering the U.S.
Your U.S. citizen does not have to file a separate petition for your children. They may be granted K-2 visas, which are based on the approval of the I-129F that your U.S. citizen filed for you, but only if they were listed in the petition. Once you and your fiance are married, you and your children may apply to adjust status to permanent resident (green card), but must do so separately. Keep in mind that your children must be unmarried and that the step-relationship between your fiance and them must have been created before the child’s 18th birthday.
You and your children can travel join you in traveling to the United States. Another option would be for them to join you later (commonly known as follow-to-join). Obviously, both you and your children must travel to the U.S. within the expiration date of the K-Visa. The children must join you however within one-year, or else they will need a separate petition.
Keep in mind that a visa approval is not a guarantee that you or your children will be admitted into the U.S. Rather, a visa is only permission to apply at a U.S. port of entry for admission. Customs and Border Protection (CBP) still have the final say as to whether you will be allowed to enter the U.S. Contact a New Jersey Immigration Lawyer now.