Adopt stance, admitting university supports El Salvador (7)
I believe the answer is:
espouse
'adopt' is the definition.
(I know that adopt can be written as espouse)
'stance admitting university supports el salvador' is the wordplay.
'stance' becomes 'pose' (I've seen this in another clue).
'admitting' is an insertion indicator (admit can mean to welcome in or accept).
'university' becomes 'u' (abbreviation for university).
'supports' is a charade indicator (letters next to each other) (bottom letters provide a support for the top ones).
'el salvador' becomes 'ES'.
'pose' going around 'u' is 'pouse'.
'pouse' put after 'es' is 'ESPOUSE'.
(Other definitions for espouse that I've seen before include "Give support to - see soup (anag)" , "Marry -- take on as a cause" , "help!" , "Take on, a cause say" , "Champion or support, as with a cause" .)