Country in South America close to Mexico and America (5)
I believe the answer is:
samoa
'country' is the definition.
(I know that Samoa is a country)
'south america close to mexico and america' is the wordplay.
'south' becomes 's' (abbreviation).
'america' becomes 'am'.
'close to' says to take the final letters (the 'close' to the word).
'and' is a charade indicator (letters next to each other).
'america' becomes 'a' (common abbreviation eg in USA).
The last letter of 'mexico' is 'o'.
's'+'am'+'o'+'a'='SAMOA'
'in' is the link.
(Other definitions for samoa that I've seen before include "Commonwealth country in the Pacific, capital Apia" , "island territory" , "SW Pacific island chain" , "Polynesian isle" , "Pacific islands state" .)