EXCLUSIVE

Soon-to-be First Lady Melania Trump is the biggest thing to come out of Slovenia since craft beer ... and we've learned the leaders of that country has already tried establishing a relationship with her and her hubby.

An official from the Embassy of the Republic of Slovenia tells us President Borut Pahor and Prime Minister Dr. Miro Cerar sent Melania a congratulatory letter after the election.

We're told the letter -- written in Slovenian -- expressed their gratitude to Melania for "raising visibility of our central-European country." Melania was born in the southeastern city of Novo Mesto.