Country star accepting Russian agreement (5)
I believe the answer is:
sudan
'country' is the definition.
(I know that Sudan is a country)
'star accepting russian agreement' is the wordplay.
'star' becomes 'sun' (the Sun is a star).
'accepting' means one lot of letters goes inside another (inserted letters are accepted).
'russian agreement' becomes 'da'.
'sun' enclosing 'da' is 'SUDAN'.
(Other definitions for sudan that I've seen before include "African region" , "Home for many Arabs" , "Country W. of Ethiopia" , "Us and the African state" , "Country in NE Africa, capital Khartoum" .)