Certified birth certificate of petitioner

Hello
Kindly need your urgent help. The problem is US Embassy don’t have proper queries resolution setup here in uae

In interview appointment letter they mentioned bring the

original and certified copy of the birth certificate
Original and certified copy of the birth certificate of spouse

Now spouse means petitioner who is at US and his birth certificate is not with us so don’t know what to do and who has to certify it … he is at US so certification has to be from USA right ? (He is born at india but US Citizen now)

Pls reply to me at the earliest
Thanks