Diplomatic agreement (6)
'diplomatic agreement' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for pact that I've seen before include "'Accord, treaty (4)'" , "Agreement, bargain" , "Settlement" , "Alliance" , "Formal agreement between parties or states" .)
(Other definitions for accord that I've seen before include "Official agreement; harmony" , "Agreement - conformity" , "Unanimity" , "concert" , "Correspond" .)