As a bilateral treaty, both China and Japan should perform the Sino-Japan United Declaration according to the principle of 'Pacta Sunt Servanda'.
《中日联合声明》是一个双边条约，中日双方都必须根据“约定必须遵守”原则履行该约。
2
First, Pacta Sunt Servanda principle is the leading principle of solving territorial disputes; international treaty is the overriding criterion of solving territorial disputes.