President-elect Donald Trump is building out his Cabinet with allies, old friends, business icons and even some former rivals. Here’s a look at who Trump has picked so far:

Exxon Mobil CEO and Chairman Rex Tillerson was nominated as secretary of state.

Rex Tillerson, Secretary of State — Despite having no government or diplomatic experience, Rex Tillerson was Trump’s choice to head the State Department. The ExxonMobil CEO’s ties to Russia and the Middle East could prove problematic during his confirmation process, though. "The thing I like best about Rex Tillerson is that he has vast experience at dealing successfully with all types of foreign governments," Trump tweeted after officially announcing the pick. Former GOP presidential nominee Mitt Romney was also a finalist for the post.

RELATED: Everyone In Donald Trump’s Cabinet

Sen. Jeff Sessions, R-Ala. speaks to media at Trump Tower in New York. Carolyn Kaster / AP

Sen. Jeff Sessions, Attorney General — The Alabama senator became the first member of the upper chamber to endorse Trump in February. As the chair of the Senate Subcommittee on Immigration, Sessions helped Trump craft a hardline immigration plan that he touted would prevent people from entering the country illegally.

Though respected by his Republican colleagues in the Senate, Sessions will likely face Democratic opposition during his nomination hearing for past controversial remarks. Sessions was appointed by President Ronald Reagan for a federal district judgeship in the 1980s, but was blocked by the Senate after being accused of making racially insensitive comments about a former colleague. Thomas Figures, an African-American, said Sessions told him to be careful what he said to “white folks” and once made a comment sympathetic to the KKK. Sessions claimed he had been joking.

General James Mattis served as Commander of U.S. Central Command until his retirement in 2013. YURI GRIPAS / Reuters

Retired Gen. James Mattis, Secretary of Defense — Mattis, a former commander of U.S. Central Command, is known for his blunt, outspoken style and his selection likely signals Trump will take an increasingly hardline stance with Iran. U.S. officials told NBC News that Mattis’ philosophy clashed with the Obama administration when it came to handling Iran and U.S. adversaries around the globe.

Mattis, known by the nickname “Mad Dog,” aggressively led a Marine division into Baghdad during the 2003 invasion in Iraq. He has openly talked about enjoying war and “brawling.” But he is also considered a “warrior monk” with a deep understanding of military strategy and planning.

Mattis, who retired in 2013, will need a Congressional waiver before he can be confirmed. A 1947 law requires a seven-year wait before an active general can head the Pentagon.

Gen. John Kelly has been nominated to head homeland security. Manuel Balce Ceneta / AP

Retired Gen. John F. Kelly, Secretary of Homeland Security — The retired four-star general led the U.S. Southern Command and commanded Marines during some of the most intense fighting in Iraq. Kelly's son, Robert, was killed in combat in Afghanistan, making him the highest-ranking military officer to lose a child during the wars in Iraq or Afghanistan. As head of homeland security, Kelly will be responsible for overseeing Trump's controversial immigration plans. As Southern Command chief, Kelly oversaw U.S. military operations in South and Central America -- including the southern border. He, like Trump, has expressed concerns over drug trafficking across the U.S.-Mexico border.

Chairman of the House Budget Committee Tom Price (R-GA) has been nominated to head the Department of Health and Human Services. JOSHUA ROBERTS / Reuters

Rep. Tom Price, Secretary of Health and Human Services — Georgia Rep. Tom Price has been one of the fiercest opponents of the Affordable Care Act and his nomination signals Trump intends to make major changes to Obama’s signature legislative accomplishment. The six-term Congressman is an orthopedic surgeon and has written a proposal that would drastically alter the health care law by offering tax credits to purchase insurance based on age.

Price describes himself as a member of the Tea Party and opposes both abortion and gay marriage. His nomination drew swift rebuke from advocates of those causes in addition to proponents of Obamacare.

Texas Gov. Rick Perry has been chosen to lead the Department of Energy. Eric Gay / AP

Former Gov. Rick Perry, Department of Energy — The former Texas governor and two-time presidential candidate has been chosen to lead the department he infamously forgot he wanted to cut. In what became known as his “oops” moment during a 2011 debate, Perry could name only two of the three departments he hoped to dismantle, ultimately failing to recall the Energy Department.

Perry, like Trump, does not believe in human-caused climate change and has close ties to the oil industry. He serves on the board of directors of the company building the controversial Dakota Access Pipeline.

The Department of Energy plays a lead role in overseeing the country’s nuclear weapons and dealing with proliferation abroad. Ernest Moniz, the current secretary of energy, played a crucial role in securing the Iran nuclear deal. As a presidential candidate, Perry was an outspoken critic of the deal.

Ben Carson was nominated as HUD secretary. STEVE MARCUS / Reuters

Ben Carson, Secretary of Housing and Urban Development - Trump’s former rival finally accepted Trump’s offer to run the Department of Housing and Urban Development after first being approached about the position before Thanksgiving. Carson rivaled Trump at the top of the polls for a time during the GOP primaries, but he ultimately fell short and endorsed the eventual nominee despite the heated rhetoric Trump directed his way.

Before his 2016 run, Carson was best known for his work as a neurosurgeon. At 33 years old, Carson became the director of pediatric neurosurgery at Johns Hopkins Children’s Center. He gained international fame for his role in helping to separate infant conjoined twins.

President-elect Donald Trump and Betsy DeVos pose for a photo after their meeting at Trump International Golf Club in Bedminster Township, New Jersey. Drew Angerer / Getty Images

Betsy DeVos, Secretary of the Department of Education — DeVos, a 58-year-old billionaire philanthropist, heads the American Federation for Children. Her group advocates for charter school education and she has been an advocate for school vouchers.

DeVos donated to Carly Fiorina and Jeb Bush during the Republican primaries, though she ultimately endorsed Marco Rubio. Bush praised Trump’s pick, saying in a statement she has, “a long and distinguished history championing the right of all parents to choose schools that best ensure their children’s success.”

Groups like the National Education Association and American Federation of Teachers have opposed her nomination, arguing her work promoting charter schools has undercut public education and corporatized the nation’s school systems.

The Michigan native is married to Dick DeVos, an heir to the Amway fortune, and is the sister of Erik Prince, founder of the government-contracted security company formerly known as Blackwater.

Montana Rep. Ryan Zinke has been selected as Interior Secretary. Matt Brown / AP

Rep. Ryan Zinke, Department of the Interior — The Montana Republican is an avid outdoorsman and has supported legislation to preserve public lands. He is a former Navy SEAL serving in just his second-term in Congress and was an early supporter of Trump. Zinke is a strong supporter of coal, oil and gas exploration and environmental advocacy groups have slammed his selection to head the department in charge of overseeing about three-quarters of federal lands and natural resources.

South Carolina Governor Nikki Haley has been nominated by Trump to lead the U.S. delation to the United Nations. KEVIN LAMARQUE / Reuters

Gov. Nikki Haley, U.S. Ambassador to the United Nations — South Carolina Gov. Nikki Haley quickly accepted Trump’s offer to become the U.S. ambassador to the United Nations after the two spent much of 2016 in a tiff. Haley endorsed Marco Rubio in the lead up the Palmetto State Primary back in February, and at one point called Trump "everything a governor doesn't want in a president." She then backed Ted Cruz after Rubio ended his run, and only tepidly endorsed Trump at the Republican National Convention in July.

Haley became the first woman Trump appointed to his Cabinet, though the 44-year-old’s nomination to lead the U.S. delegation to the UN raised some eyebrows since her foreign policy experience is limited. Haley, the daughter of Indian immigrants, served three terms in the South Carolina State House before becoming governor in 2010.

Former US Secretary of Labor Elaine Chao has been nominated to head the Department of Transportation. EDUARDO MUNOZ ALVAREZ / AFP - Getty Images

Elaine Chao, Secretary of Transportation — Trump tapped Chao, a former labor secretary, to head the Department of Transportation. Chao became the first Asian-American woman to hold a Cabinet position when President George W. Bush appointed her labor secretary. She stayed in the post for eight years, becoming the only Cabinet member to serve during Bush’s entire time in office.

Chao is married to Senate Majority Leader Mitch McConnell, and has served as director of the Peace Corps, CEO of the United Way of America. She was the deputy secretary of transportation under President H.W. Bush.

Steven Mnuchin, the national finance chair for Trump's campaign, has been nominated as Secretary of the Treasury. ANDREW GOMBERT / EPA

Steve Mnuchin, Secretary of the Treasury — Mnuchin served as the Trump campaign’s national finance chair and was largely considered the frontrunner for the job. He began his career at Goldman Sachs, where he spent 17 years and rose to become a partner. He left to start his own hedge fund and went on to become a financier of Hollywood films like “Avatar” and “American Sniper.” Throughout his career, Mnuchin showed only a limited interest in politics and remained mostly behind the scenes during Trump’s run.

Billionaire Wilbur Ross was selected to head the Commerce Department. Drew Angerer / Getty Images

Wilbur Ross, Secretary of Commerce — The 79-year-old billionaire made his fortune by buying up and restructuring companies in industries like steel and coal, the kinds of jobs that Trump has pledged to bring back. He also has been an outspoken critic of free trade agreements, which was a hallmark of Trump’s campaign. His relationship with Trump goes back decades. Ross helped Trump keep control of his failing Taj Mahal casino in the 1990s by persuading investors not to push out the real estate mogul.

Ross is expected to face questions during his confirmation about his role in the 2006 Sago Mine disaster in West Virginia. Twelve miners were killed after an explosion there shortly after his company purchased the mine. Ross said he was aware of the mine had multiple violations but said he felt comfortable sending workers into what he thought was a safe situation.

CKE Restaurants CEO Andy Puzder has been selected as Trump's secretary of labor. Jack Plunkett / AP Images for Carl's Jr.

Andy Puzder, Secretary of Labor — The head of CKE Restaurants, which includes Carl’s Jr. and Hardee’s, favors rolling back restaurant regulations and has suggested replacing fast-food employees with robots. Puzder staunchly opposes raising the minimum wage, arguing that doing so would result in fewer jobs. He was criticized earlier this year for lauding the benefits of replacing humans with automated employees because they “never take a vacation, they never show up late, there's never a slip-and-fall, or an age, sex, or race discrimination case.” Puzder’s selection also drew rebuke from conservative Breitbart News for pro-immigration views that contrast those the president-elect campaigned on.

David Shulkin, the Under Secretary of Health at the Department of Veterans Affairs, leaves a meeting with President-elect Donald Trump at Trump Tower, Monday, Jan. 9, 2017, in New York. (AP Photo/Evan Vucci) Evan Vucci / AP

David J. Shulkin, Secretary of Veterans Affairs — Shulkin is the current undersecretary for health at the VA and is one of the few Trump appointees that can be considered a Washington insider. He was appointed in 2015 by President Obama with a mandate to cut wait times for veterans seeking care after the scandal that led to the resignation of Secretary Eric K. Shinseki. “I have no doubt Dr. Shulkin will be able to lead the turnaround our Department of Veterans Affairs needs. His sole mandate will be to serve our veterans and restore the level of care we owe to our brave men and women in the military,” Trump said in a statement.

Still Outstanding

Secretary of Agriculture: Sid Miller and Heidi Heitkamp are believed to be under consideration.