WASHINGTON (CNN) -- In an emotional speech honoring the slain U.S. ambassador to Libya, Secretary of State Hillary Clinton said the United States is taking "immediate steps to bolster security and readiness at our missions across the globe."


Clinton said the State Department and the Defense Department already have dispatched joint teams to review high-threat posts "to determine whether improvements are needed in light of the evolving security challenges we now face."

U.S. diplomats serve in more than 275 posts in 170 countries around the world, Clinton noted Thursday.

Three investigations into the circumstances of Christopher Stevens' death are under way: by the FBI, Congress and the State Department's Accountability Review Board. "We will apply its recommendations and lessons learned to our security around the world," Clinton said.

The review board is expected to issue its report by early to mid-December, according to the State Department.

"We now have a formal accountability review board investigating the terrorist attack that killed Chris, and we will certainly apply its recommendations and lessons learned to improving security everywhere," Clinton said. "It's appropriate that we do so based on facts and evidence. Chris's family, his colleagues at the department, and the American people deserve nothing less."

Clinton made her remarks at the Common Ground Awards, presented annually by the international organization, Search for Common Ground, for outstanding accomplishments in conflict resolution, community building and peace building.

Stevens' sister, Anne, received the award in honor of her brother.

The ambassador's death has become the focus of intense partisan fighting.

Lawmakers want answers to many outstanding questions surrounding the September 11 armed assault on the diplomatic facility and a CIA annex in Benghazi.

Specifically, they want to know who was responsible, whether it was planned, the intelligence reporting on the threat to Libya prior the attack, and whether security was adequate.

Clinton said, "In the rush of headlines, it is easy to forget that at the center of this national tragedy was such a real person with passion and principles,with humor and irony, with ambition and humility -- with friends and colleagues and loved ones."

She described Stevens as a "true son of the West, who hiked and jogged and danced his way through the hills and forests of northern California."

"His mother liked to say he had sand in his shoes. Always moving and running and working, seeking out new challenges and adventures."

Clinton said Stevens "understood not just the science of diplomacy but the art. He heard the music and the words. And he was committed to his mission of helping others find their own freedom."

He "found a second home amid the shifting deserts and crowded cities of the Middle East," she said.

Stevens, she said, "would have been the first to say that the terrorists who attacked our mission in Benghazi on September 11 did not represent the millions of Libyans who want peace and deplore violence."

Accepting the award for her brother, Anne Stevens said he remained an optimist who took great joy in seeing the Libyan Revolution succeed.

"For us, this award is a wonderful recognition for the work Chris did and the man he was. While we are incredibly saddened that he is gone, we hope that his legacy will live on and encourage others to continue to work toward the goals that Chris believed in."

Speaking with CNN's Erin Burnett Thursday evening Anne Stevens said her brother encouraged her and her siblings to excel at everything thing they did. "He set a high bar for our family and inspired us," she said.

The State Department prepared her brother well for potential problems, Anne Stevens said. "You cannot eliminate the danger entirely."

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