I agree with Ross.
Here is a helpful definition from the Oxford Dictionary:
Statesman:-
A skilled, experienced, and respected political leader or figure.
Example: the elder statesman in the cabinet
A politician, by contrast, is more ordinary:
"A person who is professionally involved in politics, especially as a holder of an elected office:"
Note that "politician" may also be used to described a person not involved in national or regional politics but is in general a manipulator.
Example: He plays a lot of office politics. He is very political. He is a politician.