Sen. John McCain (R-Ariz.) has placed a hold on the nomination of James Clapper to serve as director of national intelligence, his office confirmed Monday.

“Senator McCain requested a specific report from Mr. Clapper and until that report is provided, Senator McCain will continue to hold his nomination,” spokeswoman Brooke Buchanan said in an e-mail.

The Senate Intelligence Committee unanimously approved Clapper’s nomination last week, and Democrats had hoped to confirm him before adjourning for the August break.

With McCain’s hold, however, that is unlikely.

President Barack Obama nominated Clapper, a retired Air Force lieutenant general currently serving as undersecretary of Defense for intelligence, in June to fill the post previously held by retired Adm. Dennis Blair. Blair stepped down in May after a rocky 16-month stint during which he had strained relations with White House officials and faced increased scrutiny following the attempted Times Square bombing, the shootings at Fort Hood, Texas, and the attempted Christmas bombing of a commercial jet over Detroit.

The director of national intelligence, a job created after 9/11, oversees 16 spy agencies.