Barely twelve hours after television networks declared Donald Trump the next president of the United States four years ago, officials at Border Patrol headquarters in Washington, D.C., quietly launched a new operation – not to capture drug smugglers or human traffickers, but to capture the attention of the Trump appointees who would be taking control of government.

“[W]e are moving fast and furious here at HQ to be prepared for the new Administration,” the agency’s head of law enforcement operations told colleagues in an email on Nov. 9, 2016, the day after the election.

The scramble that privately unfolded across government in the days immediately after the presidential election four years ago – and during almost every peaceful transition of power before then – has yet to materialize this year, as President Donald Trump continues to challenge Joe Biden’s election victory and Trump administration officials wait to officially declare Biden the winner.

“It’s a study in contrasts,” one current U.S. official said, speaking on the condition of anonymity because he was not authorized to speak publicly.

Hundreds of Border Patrol emails obtained by ABC News through a Freedom of Information Act request offer a rare glimpse into just how far government agencies usually go and how quickly they take action to prepare for a new administration – efforts that current officials say are on hold right now across the U.S. government.

“As we all know, one of President-elect Trump’s central campaign themes was ‘border security.’ With our mission a clear priority… [w]e must be ready to provide the best and most accurate information as quickly as possible in order to take advantage of every opportunity to describe who we are, what we do and what we need to get our mission accomplished,” the Border Patrol’s acting deputy chief of operations in Washington, D.C, wrote to other senior officials on Nov. 10, 2016, two days after the election four years ago.

In the days that followed, Border Patrol leadership collected information “for new fence construction” and new surveillance tools, but they also directed a handful of field offices to produce “video vignettes” about their operations that could be played for incoming administration officials.

“Scripting is key,” one Border Patrol official in Texas cautioned, before an official from headquarters offered his own advice: “Pictures of rusting pipes don’t tell compelling arguments. A 90-second video with an agent talking about who they are, where they are and how the facilities affect their ability to apprehend aliens tells a whole different story.”

Such detailed planning is not taking place right now, nor are the in-person briefings or document handoffs that are usually well underway at this time after an election, current government officials told ABC News.

In fact, current and former national security officials said that while the Trump administration’s delays in sharing policy-related materials – like those highlighted in the Border Patrol emails – may be frustrating, delays in sharing classified threat information and diplomatic intelligence concern them far more.

“That’s the dangerous thing,” according to Jordan Strauss, a former Justice Department and White House official who helped compile national security-related materials for the coming transition four years ago.

Many on Biden’s team have extensive government experience and served in high-level national security posts under the Obama administration, “but a lot can change in four years,” Strauss warned. “So there [could be] a known threat for which mitigation – starting on Day 1 – requires read-ins and knowledge of sensitive material, [but] the transition team can’t get access.”

By law, government agencies must begin compiling briefing materials for a new administration even before the election takes place. But those materials can’t be shared with the incoming administration until the General Services Administration “ascertains” the winner.

At the Defense Department, a senior official issued guidance to his entire workforce a week after the election telling staffers to “remain in pre-election mode,” according to a copy of the guidance reviewed by ABC News.

“Until the General Services Administration (GSA) Administrator has formally ascertained a winner, Departments and Agencies are NOT authorized to engage any transition team. We do not know when that will occur,” the guidance said.

At the Justice Department, many career officials – who by this time four years ago had put together binders of materials describing ongoing criminal investigations – have yet to start work on similar binders for the incoming Biden team “due to the situation,” one source familiar with the matter told ABC News.

“So nothing [more] has been prepared,” the source said.

According to the current U.S. official, those binders are usually filled with memos telling the incoming team: “Here is where you’re picking up the story, these are the things that have happened, [and] here is a list of decisions you may be asked to make in the next 60 to 90 days with respect to this [issue].”

Despite the transition standstill and guidance to stand down for now, staffers in some government agencies have been drafting additional memos, assuming that Biden will be “ascertained” the winner at some point and the memos can then be shared, the U.S. official said.

Such memos “are important,” but “many may be sitting on desks,” according to Strauss, now an executive at the global intelligence firm Kroll and its parent company Duff & Phelps.

“When you get a new computer or a new phone, there’s the one-page ‘quick start guide.’ That’s what the memos do,” added Strauss.

On Thursday, Biden himself described the delay in ascertaining a winner as “totally irresponsible,” saying “there is no excuse” for the Trump administration failing to share information and materials related to the COVID-19 pandemic in particular.

“It’s going to put us behind the eight ball by a matter of a month or more, and that’s lives [lost],” he said.