I harshly criticise a poor Asian capital (9)
I believe the answer is:
islamabad
'asian capital' is the definition.
(capital of Pakistan)
'i harshly criticise a poor' is the wordplay.
'harshly criticise' becomes 'slam'.
'poor' becomes 'bad' ('bad' can be similar in meaning to 'poor'**).
'i'+'slam'+'a'+'bad'='ISLAMABAD'
(Other definitions for islamabad that I've seen before include "Asian city" , "capital city" , "Pakistan's capital" , "city of Pakistan?" , "Capital of Pakistan" .)