Comma (n): A mark of punctuation used to indicate a division in a sentence, as in setting off a word, phrase, or clause, to separate items in a list, to mark off thousands in numerals, to separate types or levels of information in bibliographic and other data.
Consider the lowly comma.
If you regard it as a mere flyspeck with a tail, that may account for the some capricious uses (and non-uses) of it that appear from time to time.
Without a comma after “representatives” the meaning is that three new representatives are replacing three old ones.
A comma (perhaps preferably a dash) would have brought out the correct meaning, that representatives of the three countries were new to the council.
Insert a comma after “says” to set off a parenthetical phrase.
Put commas within closing quotation marks.
Use commas to separate elements in a series, and DO put a comma before the conjunction in a simple series of three or more items.
USING COMMAS WITH THE WORD “HOWEVER”:
Using “however” to begin a sentence:
If “however” is used to begin a sentence, it must be followed by a comma, and what appears after the comma must be a complete sentence.
Using “however” as an aside:
“However” can be used to interrupt a sentence. Use a comma before and a comma after “however” when you use it in this way.