IRBIL, Iraq — The U.S. Army failed to properly keep tracks of hundreds of humvees, tens of thousands of rifles and other pieces of military equipment that was sent to Iraq, according to a government audit from 2016 that was obtained by Amnesty International and released Wednesday.

The price of the equipment — meant to equip the Iraqi army, Shia militias and the Kurdish Peshmerga — totaled more than $1 billion.

“This audit provides a worrying insight into the U.S. Army’s flawed — and potentially dangerous — system for controlling millions of dollars’ worth of arms transfers to a hugely volatile region,” Patrick Wilcken, Amnesty International’s Arms Control and Human Rights researcher, said in an emailed statement.

The arms and equipment transfers were a part of the Iraq Train and Equip Fund, a program that initially appropriated $1.6 billion under the 2015 National Defense Authorization Act to help Iraqi forces combat the rise of the Islamic State. The 2017 act is slated to lend $919.5 million to the fund.

The audit found that improper record-keeping, including duplicated spreadsheets, handwritten receipts and a lack of a central database to track the transfers, contributed to the reports findings. Additionally, the audit claimed that under the Iraqi Train and Equip Fund, once the equipment was transferred to the government of Iraq, the Pentagon no longer had to monitor the material as it was no longer U.S. government property.

While likely not an issue for things such as uniform items and body armor, the lack of any post-transfer accountability on U.S. arms and munitions raises the chances for illicit diversion from the intended supply chain. Currently, the Middle East is awash in U.S. weapons and equipment, and with President Donald Trump’s decision to equip Kurdish forces in Syria with more weapons, it is unclear whether the United States has learned from any of its past mistakes in the region.

“The need for post-delivery checks is vital,” Wilcken said. “Any fragilities along the transfer chain greatly increase the risks of weapons going astray in a region where armed groups have wrought havoc and caused immense human suffering.”

The audit said the training and equipment fund’s management had initiated a “two-step corrective action plan to implement visibility and accountability systems” following concerns raised by the Pentagon’s inspector general. The audit does not detail what the corrective actions might entail. However, it would likely include greater oversight by the Pentagon’s End Use Monitoring division. The division runs the Golden Sentry Program, with the intended purpose of monitoring the transfer and stockpiles of U.S. equipment that is provided to other countries.

A 2015 audit on the Iraq Train and Equip Fund found similar issues, including almost no record-keeping on the Iraqi side.

Ian Overton, a former BBC journalist, and his team of researchers pulled 14 years of Pentagon contracts, revealing that the United States has supplied more than 1.45 million firearms to various armed groups in Afghanistan and Iraq, according to a New York Times magazine report. Those include more than 978,000 assault rifles, 266,000 pistols and almost 112,000 machine guns. It is unclear how many of those remain in possession of their intended recipients.