These are people who've been fired or resigned from Trump's White House

U.S. President Donald Trump's White House has had the highest turnover of senior-level staff of the past five presidents, according to figures compiled by the Brookings Institution think-tank.

Current administration has highest turnover of senior staff of past 5 U.S. presidents

U.S. President Donald Trump's White House has had the highest turnover of senior-level staff of the past five presidents, according to figures compiled by the Brookings Institution think tank. (Manuel Balce Ceneta/Associated Press)

U.S. President Donald Trump's White House has had the highest turnover of senior-level staff of the past five presidents, according to figures compiled by the Brookings Institution think-tank.

And the number of those leaving the West Wing may still grow.

Here are some senior figures who have been fired or quit the administration since Trump took office on Jan. 20, 2017.

2018

James Mattis - Perhaps the most respected foreign policy official in Trump's administration, James Mattis is leaving his post at the end of February after two tumultuous years struggling to moderate the U.S. president's hardline — and sometimes inconsistent — policies. In his resignation letter, Mattis told Trump he has "the right to have a Secretary of Defence whose views are better aligned with yours."

U.S. Defence Secretary James Mattis looks at President Donald Trump as he speaks during a meeting in the Oval Office of the White House on March 24, 2017. (Carlos Barria/Reuters)

Ryan Zinke - U.S. Interior Secretary Ryan Zinke, who is facing federal investigations into his travel, political activity and potential conflicts of interest, will leave the administration at year's end.

John Kelly - Trump said that White House chief of staff John Kelly will also leave his job at the end of the year. Kelly, a retired Marine Corps general, was hired to bring order to the chaotic Trump White House but ultimately fell out with his boss.

Matthew Whitaker - Trump said he will nominate William Barr to be attorney general, replacing Whitaker, who was named acting attorney general only a month ago. Whitaker replaced Jeff Sessions in the top Justice Department post. He immediately came under scrutiny over past remarks critical of a probe into Russian meddling in the 2016 U.S. presidential election and any collusion between Moscow and the Trump campaign. As acting attorney general, Whitaker took over supervision of the probe, led by Special Counsel Robert Mueller. Some lawmakers worried Trump might order Whitaker to undermine the inquiry, fears that Trump allies called unwarranted. The Senate must confirm any nominee for attorney general; Democrats immediately voiced concerns about Barr.

In this Dec. 15, 2017 photo Trump, left, appears with then U.S. Attorney General Jeff Sessions during the FBI National Academy graduation ceremony in Quantico, Va. Sessions was forced out of his job in November. (Evan Vucci/Associated Press)

Jeff Sessions - After months of being attacked and ridiculed by the president, the former senator was forced out on Nov. 7.

Nikki Haley - She said on Oct. 9 that she would step down at the end of the year as U.S. ambassador to the United Nations. Trump put forward State Department spokesperson Heather Nauert as her successor, also subject to Senate review.

Don McGahn - Trump said in August the White House counsel would leave amid strains between the two over the Mueller probe.

Scott Pruitt - The Environmental Protection Agency chief quit on July 5 under fire over a series of ethics controversies.

David Shulkin - White House officials said on March 28 that the Veteran Affairs secretary would resign.

H.R. McMaster - The national security adviser was replaced on March 22 with John Bolton.

Andrew McCabe - The deputy FBI director was fired in mid-March by Sessions.

Rex Tillerson - The secretary of state was fired by Trump on March 13 after rifts between them. On Friday, Trump tweeted that Tillerson was "dumb as a rock" and "lazy as hell."

In this Jan. 10, 2018 photo, then Secretary of State Rex Tillerson listens as Trump speaks during a cabinet meeting at the White House in Washington. Tillerson was fired by Trump on March 13 after rifts between them. (Evan Vucci/Associated Press)

Gary Cohn - The National Economic Council director and former Goldman Sachs president said on March 5 he would resign.

Hope Hicks - The White House communications director, a long-serving and trusted Trump aide, resigned on Feb. 28.

Rob Porter - The White House staff secretary resigned in February after accusations of domestic abuse from former wives.

2017

Omarosa Manigault Newman - The former reality TV star was fired as assistant to the president in December.

Then White House Director of communications for the Office of Public Liaison Omarosa Manigault, right, walks past Trump during a meeting on healthcare in the Roosevelt Room of the White House in Washington, Monday, March 13, 2017. (Pablo Martinez Monsivais/Associated Press)

Richard Cordray - The U.S. Consumer Financial Protection Bureau's first director quit in November.

Tom Price - The Health and Human Services secretary quit under pressure from Trump on Sept. 29 over travel practices.

Stephen Bannon - Trump's chief strategist was fired by Trump in mid-August after clashing with White House moderates.

Anthony Scaramucci - The White House communications director was fired by Trump in July after 10 days on the job.

Reince Priebus - Replaced as chief of staff by John Kelly, Priebus lost Trump's confidence after setbacks in Congress.

Sean Spicer - Resigned as White House press secretary in July, ending a turbulent tenure.

Walter Shaub - The head of the U.S. Office of Government Ethics, who clashed with Trump, stepped down in July.

Michael Dubke - Resigned as White House communications director in late May.

James Comey - The FBI director, who led the Russia probe before Mueller, was fired by Trump in May.

Katie Walsh - The deputy White House chief of staff was transferred out to a Republican activist group in March.

Michael Flynn - Resigned in February as Trump's national security adviser. Flynn later pleaded guilty to lying to the FBI. He is set to be sentenced in December.

Sally Yates - Trump fired the acting U.S. attorney general in January after she ordered Justice Department lawyers not to enforce Trump's immigration ban.

With files from The Associated Press