diplomatic          
adjective uk/ˌdɪp.ləˈmæt.ɪk/ us/ˌdɪp.ləˈmæt̬.ɪk/
C1 外交的
involving diplomats or the management of the relationships between countries
  diplomatic negotiations 外交谈判 
 C2 approving讲究方法的,委婉的 
acting in a way that does not cause offence
  Ask him nicely - be diplomatic. 好好向他提出请求——要委婉一些。 
 - More examples
 - Surely a diplomatic solution is preferable to war.
 - It's a new country, hoping for diplomatic recognition from the international community.
 - The US severed diplomatic relations with Cuba in 1961.
 - The governments have broken off diplomatic relations.
 - All diplomatic attempts at a peaceful solution to the crisis have been fruitless.