Veteran CIA officer Gina Haspel was sworn in as the agency's first female director Monday, hailing the "heroines" who had gone before her and expressing hope she and her team would be "role models."

The 61-year-old Haspel, a Russia specialist who spent her career in the Central Intelligence Agency's clandestine service, takes over from Mike Pompeo, whom Trump recently made his secretary of state.

Haspel was confirmed by the Senate last week in a 54-45 vote, despite the deep reservations of some lawmakers about her past involvement in the torture of terror suspects in the post-9/11 era.

"I stand on the shoulders of heroines who never sought public acclaim, but served as inspirations to the generations that came after them," Haspel said after being sworn in by Vice President Mike Pence and introduced by President Donald Trump.

"I would not be standing before you today if not for the remarkable courage and dedication displayed by generations" of women officers, she said at CIA headquarters in Virginia.

"In roles both large and small," Haspel said they "challenged stereotypes, broke down barriers and opened doors for the rest of us."

"I am deeply indebted to them and I am extremely proud to follow in their footsteps and to carry on their extraordinary legacy."

Haspel added: "I want the current CIA leadership team to be role models and mentors for our next generation of officers."

She joked about her bruising confirmation hearing, which dug into her work overseeing a secret "black site" prison in Thailand.

It was there that Al-Qaeda suspects Abu Zubaydah and Abd al-Rahim al-Nashiri were water-boarded, an interrogation technique subsequently condemned as torture.

"It has been nearly 50 years since an operations officer rose up through the ranks to become the director and after the experience of the last two months, I think I know why that is," she told officers and invited guests.

In his introductory remarks, Trump paid tribute to Haspel as "a very special person" who was uniquely qualified to lead "the most elite intelligence professionals on the planet Earth."

"Our enemies will take note: Gina is tough. She is strong. And when it comes to defending America, Gina will never, ever back down," Trump said.

The president largely avoided the controversies swirling around his presidency, including his allegations, just hours earlier, that former CIA director John Brennan was behind the investigation into his campaign's dealings.

Trump however angered some former CIA officers with his decision to thank "courageous" Congressman Devin Nunes.

A Trump supporter, Nunes has demanded documents about the investigation into Team Trump, but which the intelligence community says risks exposing sources.

Former intelligence officer David Priess said Trump's comment about Nunes was "disgusting."

"I can't imagine this comment goes over well-but, unlike the president, IC officials are respectful enough not to make a scene," Priess said.