President Trump has nominated Ronald Vitiello, a lifelong Border Patrol agent, to be assistant secretary for U.S. Immigration and Customs Enforcement, the White House announced Monday evening.

The formal announcement comes more than a month after Thomas Homan retired from his post as deputy director after holding the position since January 2017. Trump had nominated Homan as director last November, but the Senate did not move on Trump's pick before he retired in late June.

"ICE’s mission is critical to protecting national security and public safety, and the men and women of this agency continue to carry out that mission with courage, dedication, and integrity – even in the face of unfair attacks and threats. I am honored that the president has nominated me to serve as director alongside the brave men and women of ICE," Vitiello said in a statement.

Trump had been expected to formally nominate Vitiello in early June, a DHS official had told the Washington Examiner, but that process was delayed weeks for undisclosed reasons.

[Also read: Indiana Democrat Joe Donnelly breaks with liberals on ICE, noncommittal on Kavanaugh]

Vitiello has served in his acting deputy commissioner role at CBP since April 2017, and he previously led U.S. Border Patrol as its chief operating officer for a year. He signed on as a Border Patrol officer 34 years ago and has worked in Texas, Arizona, Washington, D.C., and Vermont.

"Since assuming the role of Deputy Director in late June, he has made clear his commitment to support the men and women of ICE, and ensure they are well-positioned to meet the demands of their incredibly challenging jobs," DHS Secretary Kirstjen Nielsen said in a statement issued Monday.

"Deputy Director Vitiello’s leadership experience, combined with the unique perspective that comes from more than 30 years in law enforcement, makes him especially qualified to hold this important position," she added. "I encourage the Senate to act quickly in confirming Deputy Director Vitiello’s nomination, and I look forward to continuing to work with him and the remarkable team at ICE."

Vitiello, 54, started his federal career within the Department of Homeland Security in 1985 at Border Patrol’s Laredo Station within the Laredo Sector in south-central Texas. The Chicago native began working his way through the ranks and in 1997 became deputy assistant regional director of Border Patrol’s Central Region Office in Dallas.

In 2007, Vitiello was transferred down to the Rio Grande Valley Sector in South Texas to serve as chief patrol agent of what is now the country’s highest-traffic sector for illegal immigration. He oversaw 12,000 Border Patrol personnel in that role.

He served as Border Patrol deputy chief from 2010 through July 2016 before being promoted to be executive assistant commissioner of operations support.

Homan announced in the spring that he would retire in late June. He originally retired in January 2017, but was asked by then-DHS Secretary John Kelly on the day of his retirement party to stay on until a replacement could be found. Homan agreed.

But Homan told DHS leadership this past January he intended to leave his post in June, even though his successor hadn't been selected yet.

If confirmed, Vitiello, who is second-in-command of a 60,000-person agency will technically be taking a promotion to fully oversee ICE’s 20,000 personnel. He’ll also be joining ICE in the midst of a turbulent time in the agency's existence as politicians and candidates call for it to be abolished.

[Trump promises ICE and all police: 'The radical left Dems want you out... It will never happen!']

Homan told the Washington Examiner in a phone call late last month the controversy is “ridiculous.”

In May, ICE came under fire when Attorney General Jeff Sessions said all illegal immigrants who were apprehended entering the U.S. between ports of entry, including first-time illegal entrants who arrived with children, should be referred from CBP to the Justice Department for prosecution. Minors were subsequently turned over to the Department of Health and Human Services who would then place them with a parent or family friend in the U.S. until the parent who brought them into the country either had his or her charges dropped or served jail time.

Over the last two weeks, groups advocating for the migrant families have held protests outside ICE offices over this issue, including outside ICE's Washington headquarters on Wednesday, and marches in various cities. Organizations have called for families to be reunited and ICE to be abolished.

Homan said the agency, which handles deportations and homeland security investigations, is not relevant to this specific issue. "I think a lot of the public is misinformed," he said. "For instance, you shouldn’t be protesting ICE about family separation because that happens on the border."

Homan added he was "not vilifying Border Patrol," but attempting to explain that public frustration against ICE was being wrongly directed.