President-elect Joe Biden said Monday that his transition team has encountered “roadblocks” from political leaders at both the Defense Department and Office of Management and Budget (OMB) and called on the Trump administration to provide more information to avoid hiccups that adversaries could take advantage of during the transfer of power.

“My team needs a clear picture of our force posture around the world and our operations to deter our enemies,” Biden said in remarks following a meeting with national security and foreign policy advisers in Wilmington, Del. “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.”

“We have encountered roadblocks from the political leadership at the department of defense and the Office of Management and Budget. Right now, we just aren’t getting all of the information that we need from the outgoing administration in key national security areas,” he continued. “It’s nothing short, in my view, of irresponsibility.”

Biden did not expand further on what he described as “obstruction” by outgoing Pentagon leadership, nor did he take questions following his brief remarks. 

His remarks prompted pushback from the Trump administration. 

Acting Defense Secretary Christopher Miller defended the department’s cooperation in a statement issued later Monday, saying political and career officials “have been working with the utmost professionalism to support transition activities in a compressed time schedule and they will continue to do so in a transparent and collegial manner that upholds the finest traditions of the Department.”

“The Department of Defense has conducted 164 interviews with over 400 officials, and provided over 5,000 pages of documents – far more than initially requested by Biden’s transition team,” Miller said. “DoD’s efforts already surpass those of recent administrations with over three weeks to go and we continue to schedule additional meetings for the remainder of the transition and answer any and all requests for information in our purview.”

A senior administration official described Biden’s remarks as ridiculous while adding that OMB staff would not waste time helping the transition team develop what would ultimately be failed proposals, seeming to confirm that there has been a refusal by political leaders to cooperate. The official denied that cooperation issues had anything to do with national security.

A Defense Department spokesperson said that the Pentagon has been "completely transparent" with the Biden transition team on the fiscal year 2021 budget and provided topline information on the program for fiscal years 2022 to 2026, though OMB has not yet authorized release of the full details for the 2022-2026 period. 

Biden received a virtual briefing from members of his intended Cabinet as well as leaders of his national security and foreign policy agency review teams earlier Monday afternoon.

Biden’s transition team expressed concern earlier this month about a halt in cooperation from the Pentagon, after meetings had been canceled. The Defense Department said that meetings had been put off until after Jan. 1 as part of a “mutually agreed upon” pause during the holiday, but Biden’s team said that there was no such agreement.

Biden on Monday said that the transition had received “exemplary cooperation from some agencies” and complimented career personnel who will remain in government after political appointees vacate their various positions.

Biden will be inaugurated on Jan. 20.

Cooperation between the current federal government and Biden’s transition team began at the end of November when the General Services Administration formally recognized Biden as the apparent winner of the election, following weeks of delay.

President Trump, who has granted Biden access to his daily intelligence brief, continues to contest the results of the election and falsely assert that he won. Trump claims there was massive, coordinated voter fraud in the election, but his claims have not been backed up by evidence in court. 

Biden on Monday also offered his first in-person remarks on the Christmas Day bombing in Nashville, emphasizing the need for "continuing vigilance" while thanking police and first responders.

"This bombing was a reminder of the destructive power an individual or a small group can muster and the need for continuing vigilance across the board," he said.

"I know the hearts of all Americans are with the people of Nashville as they rebuild and recover from this traumatic event."

—Updated at 6:56 p.m.