Ambassador Tina Kaidanow, senior adviser for international cooperation, has left the Pentagon, the Department of Defense confirmed to Defense News Wednesday.

Why it matters: She's the fifth top official in seven days to exit or announce their departure from the Pentagon, according to Defense News and The Hill.

The big picture: Per the two news outlets, Kaidanow left her role on Dec. 16. It was announced on Dec. 12 that Randall Schriver, the top Asia policy official, would leave his position soon. A day later, Jimmy Stewart, the acting undersecretary of defense for personnel and readiness, said he was retiring.

Steven Walker, head of the Defense Advanced Research Projects Agency, will leave in January "for an industry job," Defense News reported Tuesday.

Earlier Wednesday, the Defense Department confirmed to the military news outlet that Kari Bingen, principal deputy undersecretary of defense for intelligence, would step down next month.

What they're saying: A Department of Defense spokesperson told The Hill the service of long-time official Kaidanow was appreciated and he wishes her well.

DOD spokesperson Lt. Col. Michael Andrews told Defense News the department was "committed to the development and implementation of international cooperative programs and defense exportability efforts to foster cooperation with U.S. allies on research, development, production and support of weapons systems and related equipment."

"The department will not provide anything further on this personnel matter," Andrews added.

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