City starts to construct an international relations office (5)
I believe the answer is:
cairo
'city' is the definition.
(Cairo is an example)
'starts to construct an international relations office' is the wordplay.
'starts to' suggests taking the first letters.
The first letters of 'construct an international relations office' is 'CAIRO'.
(Other definitions for cairo that I've seen before include "Al Qahira" , "City near the Nile delta" , "North African capital" , "Egyptian capital" , "African city" .)