Instead of waiting abroad for immigrant visa processing and entering the U.S. as an immigrant, it is possible to go through quicker on a K3 visa (K3 visa for spouse and K4 visa for children) process and enter as nonimmigrant. After arriving in the U.S., separate application for Form I-485, Adjustment of Status.

K3 visa:
The K3 visa entitles the visa applicant to enter and reside in the U.S. as a nonimmigrant until the immigrant visa petition filed by the petitioner is approved and the visa applicant is able to obtain immigrant visa status.

K4 visa:
Unmarried children, under 21 years, of a K3 applicant derive K4 nonimmigrant visas status from the K3 parent if the children's names have been included in the K3 visa petition. To be eligible for K4 visa status, the child(ren) must be unmarried, eligible to be listed under the K3 visa classification and under the age of 21 at the time they enter the U.S. To get a K4 visa for the child, the parent must have a K3 visa or be in K3 status.
As the K3 visa was created using some of the procedures formerly available only to unmarried fiances, some forms and the description may refer to the alien spouse as fiance. That's fine.
Once you have the receipt of the I-130 petition, follow a multi-step procedure below. Note that you need just the receipt of I-130 petition. You don't have to wait for approval of I-130. In fact, if I-130 form is approved, you can't get a K3/K4 visa. You have to go through consular processing to get an immigrant visa.

• Fiance visa petition
  File a fiance visa petition with USCIS on behalf on your alien fiance.
• USCIS approval and transfer - NVC
  Upon approval of the fiance visa petition, USCIS transfers the case to NVC.
  National Visa Center (NVC) further processes your case and transfers it to the consulate in the fiance's home country.
• Consulate interview
  The alien fiance and his/her children below 21 years of age go through the consulate interview process.
  Consulate interview and other process must be done in the country where the marriage took place.
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In rare instances, some couples may have to attend a fraud interview if the government has any doubts whether the intended marriage is a real one.
After Arriving in the U.S.

Adjustment of status:
After you arrive in the U.S., apply for Form I-485, Adjustment of Status for alien spouse and each child. It is not necessary to get Form I-130 approved before filing I-485.

Change of status:
The K3/K4 visa holder can not change status in the U.S. to another non-immigrant visa category.

Work permit:
The K3/K4 visa holder can file the application for employment authorization.
You can file for EAD immediately after arrival (under category (a)(9)).
You can also apply for EAD at the same time as filing for AOS or after filing AOS. This procedure is same as all other applicants applying for AOS.

Social Security Number:
K3 and K4 visa holders first need to get EAD before they can apply for a social security number (SSN).
Carry your marriage certificate to the social security office to get the social security card in the new name.
The social security card will be marked "VALID FOR ONLY WITH USCIS AUTHORIZATION". That means, you need to get EAD first before you can actually work.

Travel outside the U.S:
Aliens present in the U.S. in a K3/K4 nonimmigrant visa status can travel outside of the U.S. and return using their K3/K4 visa. A person can maintain K3/K4 nonimmigrant status even after filing I-485, Adjustment of Status and does not need Advance Parole.