Republican Sen. John Cornyn said in a floor speech Thursday afternoon that the Senate would be voting soon. John McCain, R-Ariz., who opposed Haspel, is being treated for brain cancer and was absent.
But Haspel secured enough votes to win confirmation with the backing of six Democrats, including Virginia Sen.
But Senate Democrat Elizabeth Warren insisted Haspel's past connection to practices now widely seen as torture should sound the alarm bell.
McCaskill's vote against Haspel drew immediate criticism from her main Republican opponent in her tough race for re-election in a state that President Donald Trump carried easily in 2016. Joe Manchin of West Virginia, Heidi Heitkamp of North Dakota, Joe Donnelly of IN and Bill Nelson of Florida.
A 33-year veteran of the CIA, Haspel will be the first woman to lead the agency and is now serving as its acting director.More news: At Consensus, Jack Dorsey Says He Hopes Bitcoin Becomes Internet's 'Native Currency'
On Tuesday, Haspel said that with the benefit of hindsight and her experience as a senior agency leader, the enhanced interrogation program is not one that the CIA should have undertaken.
"But there's also a valid point that people I respect think she's a terrific leader", the senator added, "so I mean I've gotta weigh that out".
The Senate voted 54-45 to make Haspel the first female Central Intelligence Agency director.
She ran a black-site prison in Thailand where a high-level terrorist was detained and tortured in 2002. Also in the midst of a fraught election year, Florida Senator Bill Nelson met with Haspel personally and said that he believed she would be fit to serve.
It became clear Wednesday that Haspel would be confirmed after she won the endorsement of the Senate Intelligence Committee by a vote of 10-5. More than 100 former USA ambassadors who served both Republican and Democratic presidents sent the Senate a letter opposing Haspel, saying that despite her credentials, confirming her would give authoritarian leaders around the world the license to say US behavior is "no different from ours".More news: YANNY OR LAUREL? Audio experts weigh in on great debate
Alternatives to Haspel were tossed around within the administration, and Haspel herself offered to withdraw ahead of her confirmation hearing.
Haspel's critics argued she still wouldn't say if she thought the interrogation program was immoral.
The CIA did make classified materials about Haspel's record available to senators.
No charges were filed, but Harris wants the Justice Department to declassify an investigative report into the matter.
"My questions about Ms. Haspel's role in the destruction of videotapes relevant to discussions occurring in Congress regarding the program have not been adequately answered", Flake said in a statement announcing his opposition.More news: Mets' Cespedes sidelined with hip strain