Thomas Homan, the combative acting director of Immigration and Customs Enforcement (ICE), announced Monday that he will retire from federal service after 34 years.

In a statement, Homan said: "It has been the honor of my life to lead the men and woman of ICE for more than a year." He added that he was retiring to focus on his family and praised ICE agents for their work "in the face of unfair and false criticism from politicians and the media."

An ICE official tells Fox News that Homan initially was set to retire in January 2017 but agreed to stay on as acting director when asked by then-Department of Homeland Security (DHS) Secretary John Kelly in order to allow time for the administration to find a permanent nominee. After being informed last fall that the White House had not found a nominee, Homan was asked to accept the nomination.

Citing family considerations, Homan informed DHS leadership early this year that he planned to retire this summer and was asked by the secretary to remain in his position in the interim to assist with transition planning.

Homan has been a strong supporter of Trump's hard-line immigration policies. He has said that he is a "100 percent" supporter of the president's plan to build a wall along the U.S.-Mexico border. In February, he warned potential border crossers, "if you enter illegally, which is a crime, it’s not going to be OK anymore."

"I know Tom is looking forward to spending more time with his family, who made their own sacrifices in order for him to lead ICE. I thank them for sharing Tom with a grateful nation," current DHS Secretary Kirstjen Nielsen told department employees in an email.

Last year, Homan announced that illegal border crossings were at their lowest level in 45 years. In the 2017 fiscal year, ICE arrested more than 110,000 people -- a 42 percent increase over fiscal year 2016. During the same period, the agency removed 226,000 people from the U.S. – down 6 percent from 2016.

Homan also has not been shy about confronting the administration's critics. Last week, Homan fired back at New York Gov. Andrew Cuomo after the Democrat accused ICE of "violating the law and endangering public safety." Homan, a former NYPD officer, said Cuomo's statement were "false," "offensive," and "an insult to ICE's sworn law enforcement officers who conduct their lawful mission professionally and with integrity."

Homan also criticized elected officials in California over its status as a so-called "sanctuary state," saying that lawmakers had "chosen to prioritize politics over public safety."

When Oakland Mayor Libby Schaaf tipped off residents to an ICE raid this past February, Homan compared her to "a gang lookout yelling 'police' when a police cruiser comes in the neighborhood" and described her actions as "beyond the pale."

Fox News' Jake Gibson and The Associated Press contributed to this report.