It’s a UN. When speaking about the United Nations, the letter "U" has a consonant sound (like "you"), and therefore takes the indefinite article "a".
It’s a UN..., so we say a UN resolution, a UN official, a UN report, etc. When speaking about the United Nations, the letter "U" has a consonant sound (like "you"), and therefore takes the indefinite article "a".
It is a UN resolution adopted by the fifteen members of the Security Council.
It is an UN resolution adopted by the fifteen members of the Security Council.
Remember, the choice between "a" and "an" is based on pronunciation, not spelling, and the individual letter "U" has a consonant sound (we say "a U").
A UN official urged the leaders of the region to set aside political agendas to save lives.
I read a UN report about the global impact of climate change.
Similarly, we say "A United Nations resolution", "a united effort" (not "an united..."), "a United Kingdom resident", etc.
This is a partial list of abbreviations that also begin with the vowel "U" but are preceded by the article "a":
