That’s right, it should be an honor to prove one’s citizenship.
I'd like him to prove that he is a natural born Citizen as required by Article II of the Constitution.
No matter what your nationality, it's something you should be proud of.... even if you had to leave your birth place to become naturalized elsewhere!
All this is so of course... only if you have a wholesome and normal gratitude for a people and nation so generous that they accepted you in your illiterate poverty-only asking your allegiance in return.