The Pentagon on Monday announced that acting Army Secretary Eric Fanning is stepping aside temporarily while he awaits confirmation by the Senate.
Fanning was nominated as Army secretary in September but was designated as "acting" secretary after the former Army secretary retired in October.
The Pentagon said some members of the Senate Armed Services Committee expressed concerns over Fanning's designation pursuant to the Vacancies Act.
"I wasn't going to have a hearing while they were in violation of the law, that's you know sort of fundamental in the way I do business," he told reporters on Monday evening.
Pentagon press secretary Peter Cook said in a statement that Fanning has been carrying out his "responsibilities as required with skill."
"While the Administration believes the designation of Fanning as Acting Secretary of the Army is consistent with the Vacancies Act, as a show of comity to address these concerns, Fanning has agreed to step out of his acting role to focus on achieving confirmation in the near future," Cook said.
Roberts's home state of Kansas contains some of the locations under consideration to house those detainees, as do South Carolina and Colorado.
Since Congress has passed laws over the last several years banning moving any detainees to the U.S., the White House has suggested the president could shut down the facility using his executive authority.
A Senate Armed Services Committee spokesman said McCain was "looking to hold a hearing to consider Mr. Fanning's nomination as soon as possible" — the first step to being confirmed by the Senate.
Fanning would be the first openly gay service secretary, if confirmed.
Pentagon spokesman Navy Capt. Jeff Davis added that Fanning's decision to step aside temporarily was voluntary.
In the interim, newly sworn-in Under Secretary of the Army Patrick Murphy will serve as acting secretary, Cook said.
"We expect this move to be of a short duration and for Fanning to achieve speedy confirmation," Cook said.
"He remains one of the most qualified nominees to be a Service Secretary, having served in many senior executive positions in each of the three military departments and as Chief of Staff of the Department," he added.
This story was updated at 7:17 p.m.