President-elect Donald Trump on Sunday appointed Republican National Committee Chairman Reince Priebus as his White House chief of staff.

Trump also announced that campaign CEO Steve Bannon, the executive chairman of Breitbart News, will be his chief strategist and senior counselor. 

Trump said that Priebus and Bannon will work as “equal partners" -- as they did in the campaign -- to make the federal government “much more efficient, effective and productive.”

“Steve and Reince are highly qualified leaders who worked well together on our campaign and led us to a historic victory,” Trump said. “Now I will have them both with me in the White House as we work to make America great again.”

The appointments suggest Trump appealing to traditional Republican circles and the party's anti-establishment wing, which helped fuel the businessman's political rise.

Bannon thanked Trump for the job, saying he and Priebus will extend their partnership in Washington to “help President-elect Trump achieve his agenda.”

Priebus said Trump will be a “great president for all Americans” and expressed his gratitude for the being able to serve the president elect and the rest of the country in helping “create an economy that works for everyone, secure our borders, repeal and replace ObamaCare and destroy radical Islamic terrorism.”

Priebus was one of Trump’s most loyal lieutenants during the real estate mogul's up-and-down campaign that resulted in many Republicans, particularly GOP candidates seeking reelection, distancing themselves from Trump. 

In Trump’s victory speech after his upset win over Democratic rival Hillary Clinton, he notably praised Preibus’ efforts and loyalty.

Reaction to Trump’s picks from both parties was quick.

“Choice of @Reince as COS over Bannon seems like a strong signal that @realDonaldTrump is taking a more conventional, conservative path,” tweeted David Axelrod, a top campaign and White House adviser to President Obama.

South Carolina GOP Sen. Lindsey Graham, who was vanquished by Trump in the Republican presidential primaries and did not support his campaign, tweeted, “Congrats to @realDonaldTrump for outstanding choice @Reince to be Chief of Staff. This shows me he is serious about governing.”

However, California Democratic Rep. Adam Schiff tweeted: “Selection of Steve Bannon for senior WH role unsurprising but alarming. His alt-right, anti-Semitic, misogynistic views don't belong in WH.”

And John Weaver, a Republican strategist who worked for Ohio Gov. John Kasich's presidential campaign, tweeted, "The racist, fascist extreme right is represented footsteps from the Oval Office. Be very vigilant, America."

Priebus, an attorney, is a former RNC general counsel and chairman of the Wisconsin Republican Party. He was elected RNC chairman in 2011 and has deep ties to GOP congressional leaders, particularly House Speaker and fellow Wisconsinite Paul Ryan.

Under Bannon's tenure, the Breitbart News site pushed a nationalist, anti-establishment agenda and became one of the leading outlets of the so-called alt-right -- a movement often associated with white supremacy and a defense of "Western values."

Bannon, who became campaign CEO in August, pushed Trump to adopt more populist rhetoric and paint rival Hillary Clinton as part of a global conspiracy made up of the political, financial and media elite, bankers bent on oppressing the country's working people -- a message that carried Trump to the White House but to some, carried anti-Semitic undertones.

An ex-wife of Bannon said he expressed fear of Jews when the two battled over sending their daughters to private school nearly a decade ago, according to court papers reviewed this summer by The Associated Press. In a sworn court declaration following their divorce, Mary Louise Piccard said her ex-husband had objected to sending their twin daughters to an elite Los Angeles academy because he "didn't want the girls going to school with Jews."

A spokeswoman for Bannon denied he made those statements.

Neither Priebus nor Bannon bring significant policy experience to their new White House roles.

Bannon was notably given top billing in the press release announcing the appointments, a curious arrangement giving that White House chief of staff is typically considered the most powerful West Wing job.

Chiefs of staff in particular play a significant role in policy making, serving as a liaison to Cabinet agencies and deciding what information makes it to the president's desk. They're often one of the last people in the room with the president as major decisions are made.

Fox News' Carl Cameron, Danny Jativa and Joseph Weber and the Associated Press contributed to this report.