If you are U.S. military (SOFA), it is advisable to obtain a letter from JAG
indicating that your adopted child is also entitled to SOFA status and you intend to take the child to the U.S. for citizenship in the near future. This letter will need to be translated into the official language of the country to which you are returning and presented to the immigration officer once you enter that country.
If you are non-military related and living within the European Union, and wish to return to Europe directly from the country from which you adopt, you may apply for a Schengen Visa. If you are entering any of the following countries, you should get a Schengen Visa: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Luxembourg, the Netherlands, Norway, Portugal, Spain and Sweden.
You can obtain a Schengen visa from any of the Schengen (or you can say European Union) countries you will be traveling to or returning to, once your child has been adopted. In order to do this, you will need to request the Schengen visa while you are in the country from which you are adopting. You will need to go to the embassy of whichever country you intend to travel to or return to with your adopted child (e.g., if you are adopting in Romania and reside in the Netherlands, you would obtain the Schengen Visa from the Dutch Embassy in Bucharest). Although it may not be necessary, we advise you to try to contact the embassy where you intend to request a Schengen, prior to your traveling to adopt your child. This will help to ensure that you have all of the necessary documents required to proceed with this process at the time of your adoption. The big benefit to a Schengen visa is that you can travel to any of those countries on the same visa. Once your adopted child has an American passport, you should not need a visa for any Schengen countries.
If you are non-military related and residing outside the European Union, and wish to return to your country of residence directly from the country from which you adopt, you will need to request a visa from authorities in your country of residence. This should be arranged prior to travel. Generally speaking, there are two ways to go about this. You can contact your residence country's embassy in the country from which you are adopting, explain what you are doing and that you will be receiving a US immigration visa for your child but wish to return to your residence before completing immigration (and hope that they will comply); or you can contact the immigration authorities in your country of residence and plead your case to them. We generally recommend traveling directly to the USA to immigrate your child before returning to your current country of residence. For most western countries, once you travel back to your residence country with your child carrying a US passport, no special visa is required for entry on "tourist" visa status. Once in your country of residence, you may need to register your child with authorities and this may require some further local adoption formalities, however, to receive a residence permit for the child.