Worldwide condemnation came Monday in the wake of a video released by the Islamic State extremist group (IS) showing the beheading of 21 Egyptian Christians and the launching of Egyptian-Libyan airstrikes on IS positions in Sirte. The United States described the purported mass killing as "despicable" and "cowardly." White House press secretary Josh Earnest added in a statement that the group's barbarity "knows no bounds", noting that the killings underscore the need for a political resolution to the conflict in Libya. Pope Francis also denounced the slaying in Libya, saying they were "assassinated just for being Christian." Francis spoke off-the-cuff during an audience with a Scottish ecumenical delegation. He said: "They only said 'Jesus help me ...' The blood of our Christian brothers is testimony that cries out. Be they Catholic, Orthodox, Copts, Lutherans, it doesn't matter: They're Christian!" Secretary of State John Kerry called Egyptian Foreign Minister Sameh Shoukry to offer his condolences on behalf of the American people and strongly condemned the killings. Kerry and Egyptian Foreign minister agreed to keep in close touch as Egyptians deliberated on a response, according to a release from the State Department. UK Secretary of State for Foreign and Commonwealth Affairs, Philip Hammond said : "Such barbaric acts strengthen our determination to work with our partners to counter the expanding terrorist threat to Libya and the region." French President Francois Hollande condemned the 'savage' killings and confirmed that France and its allies are determined to fight the militants. "He expresses his concern about the extension of Daesh operations in Libya and reminds of the determination of France and its allies to fight against this group," his office said. The UN Security Council agreed to a press statement condemning the murders saying that "the members of the Security Council strongly condemned the heinous and cowardly apparent murder by (ISIL/Daesh)", stating that this crime 'demonstrates the brutality of ISIL'. "The members of the Security Council stressed again that ISIL must be defeated and that the intolerance, violence and hatred it espouses must be stamped out," the statement said. The GCC secretary general Abdel Latif Bin Rashid Al Zayani expressed the Council's supportive stand with Egyptian leadership and people in the consequences of 'this hideous crime which shock the emotions of the Arab and Muslim nations', and expressed his warm condolences to the families of victims, the government and brotherly people of the Arab Republic of Egypt, according to BNA. Sheikh Abdallah Bin Zayed Al Nahyan, UAE Foreign Minister expressed thehis country's strong condemnation saying that "the United Arab Emirates is devoting all its resources to support the efforts of Egypt to eradicate terrorism and the violence directed against its citizens and reaffirms its total support for Egypt." Lebanese former Prime Minister Saad Hariri condemned the 'ominous' killing stating that "no hideous description can be enough to condemn the carnage witnessed along the Libyan coast that claimed the lives of 21 Egyptian citizens, caught in the grip of the demons of terrorism and death squads sweeping the Arab Spring countries". Libya declared three days of mourning and ordered flags to be lowered at half-mast over official state buildings. President of the Libyan Council of Deputies, Aquila Saleh Issa underlined Libya's willingness to fully cooperate with Egypt on fighting terrorism, stating that the country will never become a haven for terrorism.