Translation:No international beverages are on hand.
I wondered the same thing. Maybe it means "drinks from other countries than the one we are in at the moment".
Initially, when I translated in German I said "zu Hand" instead of "verfügbar" and my answer was accepted. Is it really correct, or just a bad word-by-word translation that happens to be accepted? I looked it up and found the verb "zu handhaben" which means "to manage", but I'm still not sure whether "zu Hand" has any (idiomatic) meaning by itself.
An adjective before a noun will always need an ending of some sort.
so there's no der die das or ownership (mein/uns etc.), which as per my understanding trigger the "en" endingg for the adjective when the noun is plural.
"Keine" will too. As will any article or determiner at all before the adjective. Even if there's no article, you'll still need an ending, but it will be just "-e": "Internationale Getränke sind verfügbar."
The only time you don't use an ending on an adjective is when it's entirely separate from the noun, put after a verb as "verfügbar" is here.
It counts as mixed declension, aka the same as if you'd said ein or mein beforehand:
So, to trigger the Strong Inflection exception to the "-en" preceding all plurals idea, I could say "Etwas internationale Getränke sind verfügbar." (Some international drinks are available.) or even "Internationale Getränke sind verfügbar." (International drinks are available.) - or is that correct?