Country involved in formal talks (5)
I believe the answer is:
malta
'country' is the definition.
(I know that Malta is a country)
'involved in formal talks' is the wordplay.
'involved in' says the answer is hidden in the clue.
'MALTA' can be found hidden inside 'formal talks'.
(Other definitions for malta that I've seen before include "The capital is Valetta" , "Island European country" , "Mediterranean island state" , "GC island" , "seagirt republic" .)