Washington (CNN) While preparing for his new role, Secretary of State-designate Mike Pompeo reached out to every living former secretary of state, including Hillary Clinton, sources told CNN.

During a call, Clinton pressed Pompeo on retaining career diplomats, a source familiar with the conversation said.

Last month, President Donald Trump nominated Pompeo, then his CIA director, to replace Secretary of State Rex Tillerson. Pompeo will face a confirmation hearing later this week

Clinton said during a speech this month that she saw "one small glimmer of hope" in his nomination to her former role.

"When he went into the CIA, he only brought two people with him and he really relied on the career intelligence people," she remarked, according to the Washington Examiner.

Clinton and Pompeo have their own shared history in Washington.

While in Congress, Pompeo questioned Clinton regarding her private email server and the Benghazi attacks. Though the House Select Committee on Benghazi found no new evidence of wrongdoing, Pompeo and Rep. Jim Jordan, R-Ohio, filed their own addendum asserting that the incident showed that the State Department was "seemingly more concerned with politics and Secretary Clinton's legacy than with protecting its people in Benghazi."