WATCH: Biden accuses Trump’s White House of ‘obstruction’ over handling of transition

"And right now, as our nation is in a period of transition, we need to make sure that nothing is lost in the hand off between administrations. My team needs a clear picture of our force posture around the world and our operations to deter our enemies.

"We need full visibility into the budget planning underway at the Defense Department and other agencies in order to avoid any window of confusion or catch-up that our adversaries may try to exploit.

"As I said from the beginning, we have encountered road blocks from the political leadership at the Department of Defense and the Office of Management and Budget. Right now, we just aren't getting all the information that we need for the ongoing, outgoing, from the outgoing administration in key national security areas.

"It's nothing short, in my view, of irresponsibility."

Biden then pivoted to talking about the border situation between the US and Mexico, and the need to process asylum seekers with the help of the Department of Homeland Security and the Federal Emergency Management Agency.

He said that the Trump administration "has made it much harder by working to erode our capacity. It's going to take time to rebuild that capacity," he said.

On Dec. 18, numerous outlets reported that the Department of Defense had put a halt to briefings to the transition team, but these reports were refuted by the Acting Defense Secretary, who said that "The Department of Defense will continue to provide all required support to the Agency Review Team (ART) to keep our nation and her citizens safe. As of today, we have supported 139 interviews sessions more than 200 DoD personnel, 161 requests for information, and disclosed thousands of pages of non-public and classified documents, exceeding prior transitions. At no time has the Department cancelled or declined any interview."