Retired Marine Gen. John Kelly carved out a reputation as a highly respected, but often outspoken commander who could roil debate with blunt assessments or unpopular directives on issues ranging from women in combat to the treatment of detainees at the Guantanamo Bay detention center.

But the man chosen by President-elect Donald Trump to lead the Department of Homeland Security holds a more somber distinction. The battle-hardened veteran, who served three tours in Iraq, is the highest-ranking officer to lose a child in combat in Iraq or Afghanistan.

That status, as part of what the military calls a Gold Star family, puts him in the Cabinet of a presidential candidate who verbally attacked a Gold Star family: the Khans, Muslim-American immigrants who lost a son in Iraq and had criticized Trump at the Democratic National Convention.

Kelly's son, Marine 1st Lt. Robert Kelly was killed in November 2010 in Afghanistan.

Trump's choice, who joined the Marine Corps in 1970, retired this year, wrapping up a three-year post as head of U.S. Southern Command, which spanned some of the more fractious debate over the Obama administration's ultimately failed attempt to close Guantanamo.

Transition officials confirmed Trump's pick of Kelly on condition of anonymity because they weren't authorized to speak publicly before any official announcement.

If confirmed by the Senate, Kelly would take over the nation's newest federal agency. The department was formed after the Sept. 11 terror attacks to get the U.S. government better-positioned to prevent and respond to incidents.

Carolyn Kaster / AP President-elect Donald Trump talks to media as he stands with retired Marine Gen. John Kelly, right, at the Trump National Golf Club Bedminster clubhouse on Nov. 20, 2016, in Bedminster, N.J.. President-elect Donald Trump talks to media as he stands with retired Marine Gen. John Kelly, right, at the Trump National Golf Club Bedminster clubhouse on Nov. 20, 2016, in Bedminster, N.J.. (Carolyn Kaster / AP) (Carolyn Kaster / AP)

Kelly would be the fifth person to lead the department, which includes agencies that protect the president, respond to disasters, enforce immigration laws, protect the nation's coastlines and secure air travel.

His selection bolsters concerns about an increase in military influence in a Trump White House — and as Trump moves forward on his signature issue to build a wall along the southern border and go after people living in the country illegally.

In Kelly, Trump would have another four-star military officer for his administration. James Mattis, a retired four-star Marine general, is Trump's pick for defense secretary.

Immigration enforcement is a familiar issue for Kelly. Southern Command, based in South Florida, regularly works with DHS to dismantle immigrant smuggling networks. It has partnered with Immigration and Customs Enforcement in an operation targeting human smuggling into the U.S. and helped with the rescue of children arriving alone at U.S. borders.

If Trump follows up on campaign promises to toughen immigration enforcement, the department will be charged with beefing up the screening of immigrants allowed to come into the U.S., and finding additional resources to track down and deport people living here illegally. It will also need to find a place to house these immigrants while they're awaiting deportation.

Democratic leader Nancy Pelosi said she hopes "that Gen. Kelly is willing to stand up for facts, families and the Constitution."

"America will not be made great by dragging parents away from their children, by squandering billions of dollars on a wall that does little to secure the border, or by rejecting freedom of religion and echoing the darkest chapters of persecution," she said.

Scraping for federal funds and equipment to battle such problems will not be a new challenge for Kelly. At Southern Command, he was often blunt about his need for more resources to fight the drug trade.

During a 2014 hearing, he told the Senate Armed Services Committee that he didn't have the ships or surveillance assets to get more than 20 percent of the drugs leaving Colombia for the U.S.

The most contentious issue Kelly faced, though, was the push to close the Guantanamo Bay, Cuba, detention center, and proposals to bring detainees to a facility in the U.S. if they could not be sent to other nations. Lawmakers opposed closing Guantanamo, arguing it is the ideal location for terror suspects captured in the aftermath of the 9/11 attacks.

The Pentagon faced criticism for not moving more quickly to release detainees to other countries. Those decisions largely rested with the defense secretary, but Kelly absorbed some of that anger even though his job was simply to carry out the transportation of the detainee after the decision was made. He also raised concerns about the costs of moving detainees to the U.S.

While commander there, he also placed more limits on media access to Guantanamo and restricted information about hunger strikes. He believed prisoners were eating just enough to be considered hunger strikers without endangering their health in order to manipulate public opinion.

In his final Pentagon news conference, he spoke about the loss of his son — a topic he didn't often discuss publicly.

"To lose a child is — I can't imagine anything worse than that. I used to think, when I'd go to all of my trips up to Bethesda, Walter Reed, I'll go to the funerals with the secretaries of defense, that I could somehow imagine what it would be like," Kelly said.

But, he added, "when you lose one in combat, there's a — in my opinion — there's a pride that goes with it, that he didn't have to be there doing what he was doing. He wanted to be there. He volunteered."

Kelly said he gets "occasional letters from Gold Star families who are asking, 'Was it worth it?' And I always go back with this: It doesn't matter. That's not our question to ask as parents. That young person thought it was worth it, and that's the only opinion that counts."

Associated Press