(CNN) Amid the ongoing impeachment inquiry into President Donald Trump and his administration's actions regarding Ukraine, the Pentagon's chief legal officer has requested that Defense Department agencies identify, preserve and collect any and all documents relating to the provision of security assistance to Kiev.

"I write to request your assistance and cooperation in identifying, preserving, and collecting documents and other records regarding the (Ukraine Security Assistance Initiative) and in responding to anticipated requests for such materials," Paul Ney, the General Counsel of the Department of Defense, wrote in a memo Thursday to various agencies and services within the Pentagon.

The Ukraine Security Assistance Initiative is the program which included the $250 million in military aid to Ukraine that the Trump Administration froze in June, a freeze that baffled multiple US and Ukrainian officials and has led to accusations that the administration was seeking to leverage that assistance to compel the new government in Kiev to investigate Trump's political rival, former Vice President Joe Biden and his son Hunter Biden.

There is no evidence of wrongdoing by Joe or Hunter Biden.

The chief spokesman for the Pentagon called the action to preserve records relating to Ukraine "routine."

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