WASHINGTON — The election results were only hours old Wednesday when a sober team of intelligence analysts carrying black satchels and secure communications gear began preparing to give President-elect Donald Trump his first unfiltered look at the nation's secrets.

The initial presentation — to be delivered as early as today — is likely to be a read-through of the President's Daily Brief, the same, highly classified summary of security developments delivered every day to President Barack Obama. After that, U.S. intelligence officials are expected to schedule a series of meetings to apprise Trump of covert CIA operations against terrorist groups, the intercepted communications of world leaders, and satellite photos of nuclear installations in North Korea.

The sessions are designed to bring a new president up to speed on what the nation's spy agencies know and do. But with Trump, the meetings are likely to be tense encounters between wary intelligence professionals and a newly minted president-elect who has demonstrated abundant disdain for their work.

A palpable sense of dread settled on the intelligence community Wednesday as Hillary Clinton, the candidate many expected to win, conceded the race to a GOP upstart who has dismissed U.S. spy agencies' views on Russia and Syria and even threatened to order the CIA to resume the use of interrogation methods condemned as torture.

It's fear of the unknown, the Washington Post reported, citing a senior U.S. national security official, who spoke on the condition of anonymity. It's concern about what Trump is really like under all the talk and how that will play out over the next four years or even the next few months, the official said.

Michael Hayden, the retired Air Force general and former CIA director who in 2008 briefed a highly skeptical President-elect Obama on the agency's counterterrorism operations, said that intelligence officials are likely to approach their initial meetings with Trump with professionalism, but also consternation.

"I cannot remember another president-elect who has been so dismissive of intelligence received during a campaign or so suspicious of the quality and honesty of the intelligence he was about to receive," Hayden said in a telephone interview Wednesday.

The initial meetings with Trump in the coming weeks are likely to be professionally conducted, he said, but characterized by "a little caution, a little concern."

Trump has already received at least two preliminary briefings, arranged during the campaign by James Clapper Jr., director of national intelligence. But those were done out of tradition and courtesy, providing both candidates broad overviews of security issues while holding back secrets about drone strikes, eavesdropping capabilities and other covert programs.

Intelligence officials were deeply troubled early in the campaign when Trump declared that he might be inclined to instruct the CIA to resume operations to capture terrorism suspects and subject them to brutal interrogation measures, including waterboarding. That agency program was dismantled in 2009, and measures passed since then would make its resumption illegal.

Trump subsequently backed away from those comments, which were interpreted by some as empty saber-rattling.

"He could revive a program of secret prisons" overseas, said John Rizzo, former acting general counsel of the CIA, but would be likely to find it difficult to get any foreign country to agree to host one.

His other problem would be convincing the workforce at the CIA to carry out his wishes.

"There would be such pushback," said Rizzo, whose confirmation as general counsel was derailed because of his participation in crafting the so-called enhanced interrogation techniques used on al-Qaida suspects in the early 2000s. "Given what it cost the agency" in terms of reputation, "there would be extremely strong resistance."

More recently, U.S. intelligence officials have been disturbed by Trump's positions on Russia — his statements encouraging Moscow to seek to steal Clinton's emails and his refusal to accept the intelligence community's conclusion that the Kremlin was behind a cyberespionage campaign targeting Clinton and the Democratic Party.

Speculation on where former New York Mayor Rudolph Giuliani might serve in a Trump administration added to the unease among national security officials on Wednesday. The newspaper reported that one official asked whether Giuliani going to be our attorney general.