(This is my initial statement to the Neldavans. It is just a diplomatic introduction, requesting to meet with their government, and a willingness to work with them. Imagine it is an opening hail as you achieve orbit. You can add your name and ship if you like. And I have CC'd to Starfleet Command to keep them up to date.)
The Federation would respect your other alliances and would make every attempt to find a compromise with other allies. Ultimately, the Neldava must decide if the Federation will have that opportunity. In the meantime, I am prepared to meet with a representative of both powers if that is acceptable.