The allied leaders at the Potsdam Conference told Japan that it needed to surrender.

盟军领导人在波茨坦会议上告诉日本它需要投降。

In fact, the very next day, on the 17th of July, the so-called Potsdam Conference began.

事实上，就在第二天， 即 7 月 17 日，所谓的波茨坦会议开始了。