Sheriff David Clarke oversees the Milwaukee County Jail. David Clarke (Flickr) Milwaukee County Sheriff David Clarke will not join the Department of Homeland Security as an assistant secretary, his adviser Craig Peterson told The Washington Post on Saturday.

"Late Friday, Milwaukee County Sheriff David Clarke Jr. formally notified Secretary of Homeland Security John F. Kelly that he had rescinded his acceptance of the agency's offer to join DHS as an assistant secretary," Peterson said.

"Sheriff Clarke is 100 percent committed to the success of President Trump and believes his skills could be better utilized to promote the president's agenda in a more aggressive role."

Clarke previously said he would start the DHS job in June.

The news comes just weeks after Clarke was embroiled in a plagiarism controversy, after CNN's KFile reported that he had failed to properly cite sources in at least 47 parts of his master's thesis.

Clarke has also faced longtime criticism over the conditions at the Milwaukee County Jail, which he oversees. Since April 2016, one newborn baby and three inmates have died at the jail, and prosecutors have alleged that one of the deaths was caused by dehydration after jail staff cut off water access to his cell.

Clarke's job offer at the DHS was never publicly announced by the Trump administration, but Clarke had announced on a Wisconsin radio station in May that he accepted the post. He told WISN host Vicki McKenna he would work as a "liaison with the state, local, and tribal law enforcement" in the Office of Partnership and Engagement.

Soon after Clarke's announcement, dozens of Democratic lawmakers urged Homeland Security Secretary John Kelly to reject the appointment, citing concerns over the Milwaukee County Jail deaths as well as Clark's previous criticisms of the Black Lives Matter movement, which he has called a "hateful ideology."

Clarke, who has been a prominent Trump surrogate since the early days of his presidential campaign, met with President Trump in Wisconsin on Tuesday to discuss other potential roles he could fill, the Post reported.

"The sheriff is reviewing options inside and outside the government," Peterson said.

"Sheriff Clarke told Secretary Kelly he is very appreciative of the tremendous opportunity the secretary was offering, and expressed his support for the secretary and the agency."