Gina Haspel, director of the Central Intelligence Agency (CIA) nominee for President Donald Trump, speaks during a Senate Intelligence Committee confirmation hearing in Washington, D.C., on Wednesday, May 9, 2018.

With the letter, Haspel takes a stance she publicly would not take during a tense confirmation hearing before the intelligence panel last week. Facing questions about her fitness for the job partly because of her role in overseeing a secret CIA prison, Haspel stopped short of condemning the interrogation program on ethical grounds.

The tactics are widely considered torture, although proponents of the program, including former Vice President Dick Cheney , dispute that label.

In a letter to Senate Intelligence Committee Vice Chairman Mark Warner dated Monday, Haspel writes that the so-called enhanced interrogation program "is not one the CIA should have undertaken." She stresses that she will not "condemn those that made these hard calls" following the terror attacks.

Gina Haspel, President Donald Trump 's pick to lead the CIA, now says the spy agency should not have used the brutal interrogation methods it employed in the years following the Sept. 11, 2001, attacks.

Later Tuesday, Warner said he would support Haspel's nomination, joining two Democratic colleagues in supporting her and giving a major boost to her chances of becoming CIA director. The senator said he faced a "difficult decision" but felt Haspel was "forthcoming regarding her views on the interrogation program."

"I'm going to support Gina Haspel's nomination to be Director of the CIA. I also respect my colleagues who have made a different decision," Warner said in a statement.

Shortly after Warner announced his support, Sens. Heidi Heitkamp, D-N.D., and Bill Nelson, D-Fla., also said they would back Haspel, further bolstering her bid. Both senators face re-election in a state Trump won later this year.

The Senate Intelligence Committee is scheduled to vote on Haspel's nomination Wednesday. It's not yet clear when the full Senate would vote on whether to confirm her.

Two other red-state senators up for re-election this year — Joe Manchin of West Virginia and Joe Donnelly of Indiana — have announced they will support Haspel. Sen. John McCain — an Arizona Republican who was tortured during the Vietnam War — and Sen. Rand Paul, R-Ky., have both said they will oppose Trump's choice to lead the CIA.

Republicans have pressed red-state Democrats including Claire McCaskill of Missouri, Heitkamp, Manchin and Donnelly to support Haspel's confirmation. Sen. Jon Tester, a Montana Democrat up for re-election this year, has already said he will oppose her.

During the hearing last week, Haspel tried to assure lawmakers that she would not allow the use of the interrogation tactics that are broadly viewed as torture. As a candidate, Trump said he supports the use of waterboarding or worse tactics.

Repeatedly pressed about whether she would allow tactics she considers immoral, Haspel at times evaded senators' questions and noted that the CIA does not have a formal role in interrogations.

She said she would not restore "under any circumstances" an interrogation program at the CIA and supports the "higher moral standard" the U.S. holds now.