The Pentagon has opened more than 50 criminal investigations into U.S. aid to Ukraine, the agency's inspector general said.

At a briefing Thursday, Inspector General Robert Storch said the probes, which are at varying stages, are examining "procurement fraud; product substitution, theft, fraud, or corruption; and diversion."

"We have not substantiated any such allegations, though that may well change in the future," he said, according to Bloomberg.

He added that there would likely be more investigations as time goes on, "given the quantity and speed" of aid heading to Ukraine.

In a joint effort, the Pentagon, the State Department, and the U.S. Agency for International Development are spearheading the federal government's oversight of approximately $113 billion in aid and funds marked for Ukraine as part of Operation Atlantic Resolve, a U.S initiative launched under then-President Barack Obama to bolster the defenses of NATO countries.

Bloomberg reported that a similar auditing process occurred for the Iraq and Afghanistan wars.

Storch said that, so far, auditors have discovered "stresses and gaps" in supplying aid to Kyiv, with incomplete manifests for shipments sent to Ukraine through Poland being one example the audits have found.

"As a result, DoD personnel did not have required visibility and accountability of all types of equipment during the transfer process," the auditors said in a June assessment.

Still, Storch said the Pentagon "has responded well" overall to Ukraine's military assistance needs, noting the agency has "the agility to carry out what's essentially a train-and-supply mission" before Ukraine receives most of the equipment.

According to Bloomberg, more than 200 people are monitoring the aid being sent to Ukraine, and Storch's office plans to increase the number working inside the embattled country from the current 28.

One of the audits the Pentagon is currently conducting reportedly centers on 155mm artillery shells and whether the United States balanced Ukraine's need for munitions against its own reserve, training, and operations objectives.

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