Washington ( CNN ) -- President Obama paid tribute Friday to seven CIA officers killed in Afghanistan in December , calling them `` American patriots who loved their country and gave their lives to defend it . '' Obama delivered the remarks during a memorial service at CIA headquarters in Langley , Virginia . The service was closed to the media to protect the identities of undercover officers in attendance . A transcript of Obama 's speech was provided to members of the press . `` There are no words that can ease the ache in your hearts , '' Obama told families , friends and co-workers of the seven officers . `` But to their colleagues and all who served with them -- those here today , those still recovering , those watching around the world , I say : Let their sacrifice be a summons . To carry on their work . To complete this mission . To win this war and to keep our country safe . '' A suicide bomber killed the CIA officers and contractors , as well as a Jordanian intelligence official , on December 30 at a U.S. base in Khost , in southeastern Afghanistan . The bomber was within seconds of being searched by security contractors when he detonated his explosives , a former intelligence official with knowledge of the incident said in January . Two of those killed were contractors with private security firm Xe , formerly known as Blackwater , a former intelligence official said . The CIA considers contractors to be officers . Former CIA official Robert Richer called the bombing the greatest loss of life for the agency since the 1983 bombing of the U.S. Embassy in Beirut , Lebanon , which killed eight agents . `` These remarkable men and women are the story of America , '' CIA Director Leon Panetta said at Friday 's service , according to the transcript . `` They are the heart and soul of this great country . Their devotion to duty is the foundation of our country . '' U.S. and Jordanian officials say the bomber , Humam Khalil Abu-Mulal al-Balawi , had been recruited as a counterterrorism intelligence agent , despite concerns over his extremist views , and was being used in the hunt for a senior al Qaeda figure . The suicide bombing was `` a huge blow , symbolically and tactically , '' because it eliminated so many CIA officers , who can take years to become ingrained in the region , said Reva Bhalla , director of analysis for Stratfor , an international intelligence company . In addition , she said , the attack showed the ability of the Taliban to penetrate perhaps the most difficult of targets : a CIA base . But Panetta issued a strong statement at the service Friday , assuring those in attendance that `` we will carry this fight to the enemy . '' `` Our resolve is unbroken , our energy undiminished and our dedication to each other and to our nation unshakable , '' Panetta said .
`` Let their sacrifice be a summons , '' Obama says . Service held Friday morning at CIA headquarters in Langley , Virginia . 7 CIA officers were killed December 30 in suicide bombing in Afghanistan . Intelligence analyst says suicide bombing was `` a huge blow , symbolically and tactically ''