Asian city keeps invading American city (5)
I believe the answer is:
lhasa
'asian city' is the definition.
'lhasa' can be an answer for 'city' (Lhasa is an example). I am not sure about the 'asian' bit.
'keeps invading american city' is the wordplay.
'keeps' becomes 'has' (keep can mean to have or possess).
'invading' indicates putting letters inside.
'american city' becomes 'LA' (short for Los Angeles).
'has' placed inside 'la' is 'LHASA'.
Can you help me to learn more?
(Other definitions for lhasa that I've seen before include "Group; stripe" , "Tibetan capital" , "Luxembourg's a" , "Asian capital" , "The Forbidden City in Tibet" .)