President-elect Donald Trump continued to fill out his administration Friday, by tapping some of his most prominent supporters for top posts.

Trump will nominate Alabama Sen. Jeff Sessions for Attorney General, Kansas Rep. Mike Pompeo as director of the Central Intelligence Agency and Lt. Gen. Michael Flynn as national security adviser, his transition team announced Friday.

Sessions and Flynn were among Trump’s most vocal advocates throughout the campaign and both have made controversial comments about minorities. Pompeo is a conservative firebrand and fierce Obama administration critic.

All three have years of experience in Washington and all bucked the GOP leadership to support Trump early on in his campaign.

Here’s more on Trump’s latest picks:

Sen. Jeff Sessions for attorney general

Trump has tapped Sessions as his attorney general pick, the president-elect's transition team confirmed Friday.

In February, the Alabama senator became the first sitting senator to endorse Trump during his campaign. His name was also floated as a possible running mate for Trump.

Sessions is chairman of the Senate Subcommittee on Immigration, and served as an adviser on Trump's immigration policy plan during his campaign.

When he first endorsed Trump, Sessions praised the then-GOP contender as someone who would finally fix illegal immigration.

As a current member of the Senate, it's unlikely that Sessions' Republican colleagues will try to block his nomination. But Democrats and liberal groups are sure to focus on Sessions' controversial past.

In the 1980s, Sessions was considered for a Ronald Reagan-appointed federal district judgeship in Alabama, but was blocked by the Senate after a black former deputy, Thomas Figures, accused him of making racially insensitive statements. Figures, a former assistant U.S. Attorney in Alabama, said that Sessions had once warned him to be careful about what he said to "white folks."

Rep. Luis Gutierrez, D-Ill., said in a statement that, “No Senator has fought harder against the hopes and aspirations of Latinos, immigrants, and people of color than Sen. Sessions.”

Ret. Lt. Gen. Mike Flynn for national security adviser

Flynn — a controversial figure who has been known to eschew "political correctness" — is a Trump loyalist who stayed by the candidate's side even as other national security experts sharply criticized him during the campaign.

NBC News reported in July that Trump's team vetted Flynn as a possible vice presidential running mate.

But Trump has offered Flynn the job as a national security adviser.

The special assistant to the president for national security affairs coordinates the synthesis and presentation of the information generated by the vast U.S. national security apparatus — the State Department, the Defense Department, the CIA, the National Security Agency and a host of other intelligence agencies. The national security adviser serves as the president's top day-to-day counselor on foreign and military affairs.

Flynn's appointment doesn't require confirmation by the Senate.

Flynn, 57, a 33-year veteran of the Army, was director of the Defense Intelligence Agency from 2012 to 2014.

As speculation about Flynn's appointment spread Thursday night, critics highlighted some of his controversial past statements. In February, Flynn said on Twitter that "fear of Muslims is rational."

Fear of Muslims is RATIONAL: please forward this to others: the truth fears no questions... https://t.co/NLIfKFD9lU — General Flynn (@GenFlynn) February 27, 2016

Shortly after the announcement, Democratic Rep. Elijah Cummings sent a letter to Vice President-elect Mike Pence, who is leading Trump’s transition effort, questioning possible conflicts of interest Flynn may have because of his work consulting foreign clients.

Multiple senior intelligence officials told NBC News on Friday that they have deep reservations about Trump tapping Flynn for the post.

They described him as a “hot head” with an abusive leadership style who would threaten to purge subordinates who disagreed with him. One called him “shallow and reactionary.”

Beyond his leadership style, the officials worried that his narrow views of important foreign policy hot spots could lead to long-term erosion of US power and influence overseas.

“He doesn’t understand the magnitude of the job,” said one former intelligence official.

Rep. Mike Pompeo for CIA director

Kansas Rep. Mike Pompeo has accepted Trump's offer to be CIA chief in his new administration, the transition team announced.

Pompeo said he was "honored and humbled." He said accepting it was "a difficult decision."

"I have genuinely loved representing the people of Kansas in Congress — working to make our community stronger and more prosperous," Pompeo said in a statement. "But ultimately the opportunity to lead the world’s finest intelligence warriors, who labor tirelessly to keep this nation and Kansas safe, is a call to service I cannot ignore."

Pompeo, a 52-year-old Wichita Republican, was elected to Congress in 2010 as part of the wave endorsed by the tea party and backed by Republican mega-donors Charles and David Koch. He is a former Army officer and Harvard graduate who serves on the House Intelligence Committee.

He was also a vocal member of the House Select Benghazi Committee, a special panel convened to probe the Sept. 11, 2012, attack in Libya that left four Americans dead, including U.S. Ambassador Chris Stevens.

Pompeo and Rep. Jim Jordan, R-Ohio, released their own report criticizing former Secretary of State Hillary Clinton in her role at the time, saying she misled Americans about how the attack evolved because President Barack Obama was up for re-election.

Pompeo has gotten backlash from past remarks about Muslims after saying on the House floor in 2013 that Islamic leaders failed to widely condemn the Boston marathon bombing — and appeared "complicit" in the attack.

"Instead of responding, silence has made these Islamic leaders across America potentially complicit in these acts and more importantly still, in those that may well follow," Pompeo said.

Still, many CIA insiders told NBC News they are pleased with the pick, calling Pompeo a much more favorable option than other names that have been floated. He has been regularly interacting with the agency because of his work as a member of the House Permanent Subcommittee on Intelligence.

California Rep. Adam Schiff, the top Democrat on the House Intelligence Committee, called Pompeo “very bright and hard working."