Speaking Thursday at a ceremony honoring Christopher Stephens and others, Clinton said the departments of State and Defense are investigating the security needs of high-threat postings such as Libya, Voice of America reported.
An attack on the U.S. consulate in Benghazi, Libya, Sept. 11 killed Stevens and three others.
The State Department's Accountability Review Board, as well as the FBI and Congress, are investigating what led up Steven's death and will apply the finds to improving security at all U.S. missions.
Clinton said: "Chris's family, his colleagues at the department, and the American people deserve nothing less," CNN reported.
She praised Stevens as a "fallen hero," saying "Chris understood that most people, in Libya or anywhere, reject the extremist arguments that violence and death are the only way to reclaim dignity and achieve justice."
Clinton posthumously presented Stevens with a Common Ground award, which was accepted by his sister, Anne.
The international organization Search for Common Grounds presents the award each year for outstanding accomplishments in conflict resolution, community building and peace building.