Pronunciation Problem

[Deepurple]

If an abbreviation/Initialism is preceded by the definite article, what is the pronunciation of the "definite article"(i.e. thee or the)? For example,
the USA (Is it pronounced "the"?)
the ICAC/HKMA (Are they pronounced "thee"?)
If yes, what is the rule behind this, i.e. the use of "thee" or "the" in pronunciation?
Thank you for helping.

[Barb_D]

If the abbreviation starts with a vowel SOUND (not a vowel), then you'd use the thee pronunciation. Thee FBI.

But you'll find in actuality it's slurred. Th'eff bee eye.