US failed to accurately track about $1 billion in arms sent to Ukraine: Watchdog

American personnel failed to adequately track roughly a billion dollars worth of sophisticated U.S. weaponry supplied to Ukraine, falling short of the Pentagon's rigorous security measures for arms that contain sensitive technology or are vulnerable to diversion or misuse, according to a report released Thursday from the Defense Department's inspector general.

Inspector General Robert Storch found that while accounting practices have improved since Russia's invasion began, as of last June, tracking of more than half of the U.S.-supplied Javelins, Stinger missiles, night-vision devices and other defense articles subject to enhanced end-use monitoring standards sent to Ukraine "remained delinquent."

The total value of the equipment in question is $1.7 billion.

The report, in redacted form, does not allege that any of the weaponry was misused, stating, "it was beyond the scope of our evaluation to determine whether there has been diversion of such assistance."

Administration officials have also stressed that the report is based off data that is more than six months old and argued that the meticulous requirements of enhanced end use monitoring are often impractical during an active conflict.

However, Storch testified to Congress in March 2023 that enhanced end use monitoring was "vitally important to ensure that the lethal and non-lethal tools the U.S. supplies to its partners are accounted for appropriately and being used for their intended purpose," raising questions about whether the current systems in place can accomplish those aims if requirements are not met.

At the time of his testimony, Storch told lawmakers that enhanced end use monitoring in Ukraine "was being conducted largely in accordance with the law," but his office raised concerns about compliance several weeks later.

The report concludes that the documented failures are due to the limited number of personnel conducting the work and restrictions on their movement within Ukraine, as well as the absence of procedures for end use monitoring until December 2022.

It also found that compliance had improved overall by 27% from February to June of 2023, but that "significant personnel limitations and accountability challenges remain."

The report comes as the Biden administration's latest request for funding to support Ukraine has stalled on Capitol Hill, with Republicans insisting that the emergency aid should be linked to stricter border security provisions.

Since Russia launched its invasion of Ukraine in February 2022, the U.S. has directed more than $75 billion in assistance to the country.