"召开干部会议" can be translated into English as "hold a cadre meeting" or "convene a干部（cadre） meeting".
"Hold a meeting" is a common and straightforward way to express the idea of organizing or conducting a meeting.
"Convene" is a more formal verb that means to bring people together for a meeting or assembly, and it can also be used in this context.
Both translations are acceptable, and the choice between them may depend on the specific context and the level of formality required.