The government watchdog found the money was withheld "for a policy reason, which is not permitted under the Impoundment Control Act."
The Trump Administration violated the law by withholding military aid to Ukraine, the U.S. Government Accountability Office said in a decision released Thursday.
"In the summer of 2019, the Office of Management and Budget (OMB) withheld from obligation funds appropriated to the Department of Defense (DOD) for security assistance to Ukraine," the ruling said.
"Faithful execution of the law does not permit the President to substitute his own policy priorities for those that Congress has enacted into law. OMB withheld funds for a policy reason, which is not permitted under the Impoundment Control Act (ICA). The withholding was not a programmatic delay. Therefore, we conclude that OMB violated the ICA."
The ruling was released hours before senators were set to be sworn in for President Donald Trump's impeachment trial. The House impeached the president for abuse of power, alleging that the president withheld the Ukraine aid for personal and political gain, as well as for obstructing the congressional probe into the hold.
Sen. Chris Van Hollen, D-Md., tweetedthat the ruling by the government watchdog demonstrates "without a doubt" that "the president himself ordered this illegal act."