President-elect Joe Biden’s explosive allegation this week that the outgoing Trump administration is throwing up “roadblocks” on key national security matters was a low-point for a transition plagued by mistrust, overseen by a sitting President uninterested in facilitating a smooth transfer of power. Afterward, Trump administration officials insisted Biden was stretching the truth when he said during remarks Monday that members of his team “just aren’t getting all the information that we need.” Those officials cited dozens of transition meetings that have occurred since the process officially began last month after a lengthy delay. At the same time, people close to the transition efforts said critical information about budgets, US force posture, recently announced troop withdrawal plans and the recent cyber attack attributed to Russia are being withheld. And Trump administration officials acknowledged they are wary of any transition activity that could provide the Biden team a head start in dismantling President Donald Trump’s priorities, such as his border wall construction. The resulting situation is one national security experts say could be dangerous at a vulnerable juncture for American interests. It has amounted to the most contentious presidential transition in decades, even as Biden acknowledged, in certain areas, things are running smoothly. “We are in a holiday. But we are also in the danger zone. Trump officials need to wake up and do what’s right for the nation,” tweeted retired US Navy Adm. James Stavridis, the former NATO Supreme Allied Commander-Europe, describing the current scenario a “clear and present danger to national security.” Biden advisers told CNN it is critical for the transition team to have a full understanding of the Defense Department’s operations, including on major issues such as Covid-19, cyber security (including the recent hack attributed to Russia) and the budget. Their overarching concern – which Biden made clear in his remarks in Wilmington, Delaware, on Monday – is that a lack of cooperation from the Trump administration now could have serious implications for the country’s national security and the welfare of service members during the transition period and into Biden’s presidency. Pervading the transition efforts is Trump’s refusal to concede the election, which he continues to falsely claim was riddled with fraud. From his winter vacation in Palm Beach, Trump has been excitedly discussing the prospect of the Electoral College results being overturned on January 6, the date Congress will meet to ratify them. Without Trump’s express direction to conduct a smooth transition, officials said agencies have been left to interpret for themselves how to proceed. For some, that has proven politically fraught given the President’s ongoing efforts to overturn the results. That is a far cry from Trump’s own transition, which – in his own telling – included discussion of sensitive national security matters in the Oval Office with his outgoing predecessor. The President has recounted several times his conversation with President Barack Obama about North Korea in particular. Now, Trump is refusing to meet with Biden and officials on Biden’s team insist similarly important information is being withheld from them three weeks before Inauguration Day. “It kind of comes back to the lack of visibility that we have right now into a number of critical issues relating to military operations because of (Department of Defense)’s obstruction and roadblocks,” Biden’s national security adviser, Jake Sullivan, said Tuesday in an interview on National Public Radio. “And that will mean that we are going to have to take time at the beginning of the administration after January 20 to take a hard look at how we’re postured, and what threats we’re up against, and what continuing the drawdowns look like in the way of risk to force and other considerations.” Sullivan said the Pentagon hasn’t agreed to a meeting with Biden’s transition team since December 18. “Literally dozens of written requests for information are outstanding as we speak,” he said. A clear picture The stand-off appears to be felt most acutely at the Pentagon, one of the agencies Biden singled out in his remarks on Monday. “My team needs a clear picture of our force posture around the world and our operations to deter our enemies,” he said. “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.” A person working with Biden’s landing team at the Pentagon said there are concerns that officials representing the incoming administration are not getting sufficient details on force posture, withdrawal plans, assessments on enemy activities – and almost nothing on Russia, which has recently been blamed for a massive cyber hack affecting US government agencies. A senior Defense official said the Pentagon was withholding certain budgetary information from the transition, which could cause a delay in the Biden team’s ability to submit its own defense budget on time next year. A Pentagon spokesman said Tuesday the Defense Department “has been completely transparent the Biden-Harris Transition Team on the fiscal 2021 budget. We have also provided topline information on the fiscal 2022-2026 program to the Biden-Harris Transition Team.” But the spokesman said that “The Office of Management and Budget has not yet authorized the release of the full details of the FY22-26 program.” When Biden’s team has had follow-up questions to the information they have received, the process – which calls for answers to go back through an approval process at the Pentagon – has proved to be lengthy, officials said. The Pentagon has been clear it is prioritizing requests for information received from the Biden team focused on coronavirus and Operation Warp Speed, the administration’s vaccine effort, which could also mean that other requests are not being processed in a timely manner. After Biden warned Monday of “roadblocks” in the transition process, a Defense Department spokesperson told CNN that there are three briefings/interviews scheduled for this week with the Biden transition team. Two of the briefings pertain to coronavirus issues and the other one is on “cybersecurity.” Acting Defense Secretary Christopher Miller defended the Pentagon’s transition work in a statement, touting the department’s “164 interviews with over 400 officials” and saying the agency has “provided over 5,000 pages of documents – far more than initially requested by Biden’s transition team.” Still, a source familiar with the situation told CNN that critical meetings remain outstanding. The Trump administration has announced significant troop drawdown plans in recent months, including in Afghanistan, Iraq and Somalia, even as it demonstrates military might amid heightened tensions with Iran – including the rare announcement last week that a US Navy nuclear-powered guided-missile submarine transited the Strait of Hormuz. The Pentagon is also among the US agencies confronting potential damage from the alleged Russian hacking. Last week, Biden said that the Defense Department had refused to brief his team on the massive cyberattack on government agencies and major American technology and accounting companies. The week prior, Biden’s transition team said they had not agreed to a two-week break in the discussions with Pentagon officials, despite the acting defense secretary saying that both sides had agreed to take a “holiday pause.” A transition official told CNN that the Defense Department continues to “deny and delay” meetings with agency review team members. “There has been no substantial progress since transition officials spoke to the intransigence of the department’s political leadership earlier this month,” the transition official said. “As the President-elect alluded to, no department is more pivotal to our national security than the Department of Defense, and an unwillingness to work together could have consequences well beyond January 20,” the official added. Defense Department spokesperson Sue Gough denied accusations that information has been withheld. “Any allegations that we have not been providing information on troop numbers or force posture to the (Defense Department) Agency Review Team is inaccurate,” Gough said in a statement to CNN. “The ART has met with nearly all of the commanders of the geographic combatant commands … the Chairman of the Joint Chiefs of Staff and the Vice Chairman.” The team has “interviewed Deputy Assistant Secretaries of Defense with geographic troop deployment responsibilities” and “met with the commanders of the functional combatant commands,” Gough added, and next week will “interview the commanders of U.S. Africa Command, U.S. Forces Korea, and Operation Resolute Support – Afghanistan.” Trump has installed loyalists at the top of the Pentagon after firing Mark Esper as defense secretary and replacing him with Miller. In particular, Miller’s chief of staff, Kash Patel, is viewed as having a direct line to the White House. The Pentagon has said that during the transition Patel’s “goal is to be the touch point for the secretary and ensure the secretary has insight into what’s going on and to make sure that the transition is successful.” Changes coming Biden has not made secret his plans to reverse many Trump administration priorities, including the border wall. Officials close to the White House described an attitude among Trump’s team of general reluctance to assist Biden’s team on reversing course on those items. It’s unclear whether any specific directive has been sent from the President on hampering transition activities. Aides say Trump remains solely focused on overturning the results of the election, and hasn’t paid particular mind to the transition activities that are currently occurring at agencies. He has no plans to meet with Biden himself. But one official said Trump has expressed concerns that Biden’s team is looking for ways to erase his agenda items such as the border wall, and has also suggested, without evidence, that Biden’s team is leaking information about his administration. Other officials also expressed concern that information provided to the Biden team could be leaked or made public, though there hasn’t been any evidence of that happening in the weeks since transition meetings began. A senior administration official insisted Tuesday that Biden was being untruthful in his claims that Office of Management and Budget is blocking transition activities – but acknowledged resistance from Trump’s team to Biden’s agenda priorities. The official said OMB has provided factual evidence about ongoing programs to Biden’s team over the course of 45 meetings since the transition began. But, the official said, the Trump team is not assisting in implementing what they view as failed budget proposals or hairbrained ideas, specifically listing blocking the border wall as an area Trump’s team wouldn’t cooperate. Instead the official said OMB remained focused on implementing Trump’s agenda until he leaves office. Experts said the danger in failing to clearly and fully communicate during a transition is that it undermines the incoming administration’s ability to be ready for crises that might erupt – a dynamic the US has seen once before with tragic results. Several former officials pointed to 9/11 Commission findings that the shortened transition between the administrations of former presidents Bill Clinton and George W. Bush, due to the Bush v. Gore court fight over election results, undercut communication and readiness in ways that had deadly national security implications. “National security crises are always difficult to deal with. They’re more difficult when you have a new team in place … and even more difficult when the team coming in is operating without the full picture,” said Richard Fontaine, CEO of Center for a New American Security. Former administration officials such as Fontaine say the urgency that drives agency review teams during a transition has to do with the overwhelming demands that begin at 12:01 pm on January 20. “You have a finite amount of time before officials are responsible for everything; they have an overflowing inbox immediately, meetings to go to all day, things flying at them and if they haven’t had time to do the prep work to understand the programs, policies, people then it makes it harder to deal with potential crises as they arrive,” Fontaine said. The failure to fully brief transition teams “could be dangerous in the sense that the better equipped the new team is to start on January 20 then the better off we’ll be as a country, and the worse prepared they are, the worse off we’ll be.” Some experts said concerns that the US wouldn’t be able to respond in the event of an unforeseen attack in the days surrounding Biden’s January 20 inauguration are overblown because the military is on duty regardless of who is in power. “I would definitely call it petty and irresponsible, but it is not endangering the security of the United States,” said Mark Cancian, a senior adviser with the Center for Strategic and International Studies who has worked at the Defense Department and at the Office of Management and Budget. Still, the reluctance in sharing information comes amid an already delayed transition that began weeks later than normal, giving Biden’s team a truncated window to get up to speed on critical issues. “Now we’re hearing that even with that ascertainment, the federal government is not fully participating in the transition process,” Sam Vinograd, a former National Security Council official and CNN analyst, told CNN’s Brianna Keilar. “That creates a lot of national security risk in part because we’re in the middle of a pandemic and an ongoing cyberattack.” “While Trump and his political appointees may think that they’re hurting Joe Biden, they’re actually hurting all of us,” she said. This story has been updated with a statement from Defense Department spokesperson Sue Gough.