Thank you for your question -- hopefully we can help! First, here's a look at the pet import requirements for the United States along with a few essential pet travel tips. These links contain much of what you'll need to know in order to move a pet safely from Romania to the United States.
Since crate training is one of the most important keys to planning safe pet travel, this appears to be one of your biggest challenges. Ideally the dog will have a chance to get used to being in a travel kennel (here are a few tips for crate training that apply to both dogs and cats) so that the trip won't be so stressful. If your dog is not used to being confined at all, this is something you'll need to address before any travel is undertaken (note that sedation is not an option -- it's neither permitted nor safe).
The vet you end up selecting may be able to help you with advice/training techniques, as well. Either way, it sounds like you'll need to spend some time acclimating the dog to get ready for traveling as well as life with you in the United States before attempting the transport.
Feel free to contact us if we can be of further assistance, and good luck with everything!