Leaders of France invited Japanese into Pacific nation (4)
I believe the answer is:
fiji
'pacific nation' is the definition.
(country in the Pacific Ocean)
'leaders of france invited japanese into' is the wordplay.
'leaders of' says to take the initial letters.
The initial letters of 'france invited japanese into' is 'FIJI'.
(Other definitions for fiji that I've seen before include "South Pacific republic, capital Suva" , "Country of many islands" , "Island country 1,300 miles north-east of New Zealand" , "Pacific island member of the Commonwealth, capital Suva" , "Pacific island country" .)