Who is General John Kelly, Trump's Replacement for Reince Priebus as Chief of Staff?

Updated | General John F. Kelly is taking over for Reince Priebus as White House chief of staff, President Donald Trump announced via a tweet on Friday afternoon. The news came after days of reports about tensions between Priebus and the administration's new director of communications, Anthony Scaramucci.

Kelly since January has been secretary of the Department of Homeland Security, after Trump nominated him for the position. The 67-year-old Kelly is a retired Marine Corps general who held senior command positions in Iraq and served as the combatant commander of the United States Southern Command. He was also senior military assistant to two secretaries of defense, Robert Gates and Leon Panetta.

Related: Elaine Duke likely to become acting Homeland Security secretary

Kelly has taken a hard stance on border security and support for the military. He has supported Trump's plan to construct a wall along the United States border with Mexico, calling it "essential" in order to stem "tremendous threats," though he has said that a physical barrier alone "will not do the job." He has also spoken about the threat posed by extremists, saying, "It's everywhere. It's constant. It's nonstop."

The retired general grew up in Boston and enlisted in the Marine Corps in 1970. He later attended the University of Massachusetts and returned to the Marines. He is married, and three of his children have served in the Marines and one has been an FBI agent. (His son Robert was killed while on duty in Afghanistan in 2010.) "I believe in America and the principles upon which our country and way of life are guaranteed," he said in January during his confirmation hearing to become homeland security secretary. "I believe in respect, tolerance and diversity of opinion. I have a profound respect for the rule of law and will always strive to uphold it. I have never had a problem speaking truth to power, and I firmly believe that those in power deserve full candor and my honest assessment and recommendations."

Minutes after the announcement on Friday, Trump tweeted, "I would like to thank Reince Priebus for his service and dedication to his country. We accomplished a lot together and I am proud of him!"

Kelly and Priebus brought very different backgrounds to the White House. While the new chief of staff has vast military experience, Priebus came from the GOP establishment, having been the longest-serving chairman of the Republican National Committee. Prior to becoming the chairman in 2011, he had been its general counsel.

In his six months as Homeland Security secretary, Kelly developed a positive reputation, according to insiders. "He's quickly been able to boost morale around the department and he's seen as a hands-on leader," says James Norton, who was a deputy assistant secretary at Homeland Security under President George W. Bush and is now a strategist and adviser. "He's seen as one of the stars at this point in the administration."

Trump said as much during a speech Friday on Long Island, hours before the announcement: "I want to congratulate John Kelly, who has done an incredible job as secretary of Homeland Security. One of our real stars. Truly one of our stars."

Speculation about Priebus's ouster had grown since the hiring of Scaramucci. The new communications director told CNN on Thursday about his relationship with Priebus: "I don't know if this is repairable or not." He also told The New Yorker's Ryan Lizza that he believed Priebus was leaking information and called him a "paranoid schizophrenic." Kimberly Guilfoyle, a Fox News co-host who had dinner with Trump, Scaramucci and others on Wednesday, also reportedly told the president that Priebus needed to go.

Priebus resigned on Thursday, CNN reported shortly after Trump's announcement about Kelly, citing a source close to Priebus. Speaking with CNN's Wolf Blitzer later on Friday, Priebus said, "I think the president wanted to go in a different direction. I support him in that." The outgoing chief of staff declined to comment on Scaramucci's comments about him. "It's over. I'm moving on," he said.

With Kelly gone from Homeland Security, Elaine Duke, the current deputy secretary, could become acting secretary. Democratic members of the House Committee on Homeland Security have already criticized what they said seems like a hasty decision to remove the department secretary and install him elsewhere. "Unfortunately, as with most major decisions in this administration, it is clear that this was rushed and not well thought out," Representative Bennie Thompson, ranking member of the committee, said in a statement. "The president must now replace Secretary Kelly with someone who is experienced, measured and understands that homeland security is not a partisan issue."

This article has been updated to include more information about General John Kelly and his transition to White House chief of staff.