It’s a united. Use "a" before words which sound like they start with a consonant, even if the first letter is a vowel. The word united begins with a consonant sound (you), so it takes the article “a”.
It’s a united. Use "a" before words that begin with a consonant sound, even if the first letter is a vowel. The word united begins with a consonant sound ("you"), so it takes the indefinite article “a”.
Those challenges require a united response.
Those challenges require an united response.
More examples:
There should be a united determination to tackle corruption and poverty in those countries.
There is a united effort by non-profit organizations to prevent and reduce plastic pollution.
Similarly, we say a United Nations (or a UN), a UNESCO, a United States, a United Kingdom, and a UK.
He is a United Nations official.
She is a United States senator.
A partial list of words that begin with the vowel “u” and take the article “a”:
