The hands of the UN are stained with blood due to its failure to stop the atrocities of the Assad regime in Syria, Prime Minister David Cameron told the General Assembly yesterday.
He cited a recent Save the Children report documenting the torture and murder of children by regime forces in Syria, saying: "The blood of these young children is a terrible stain on the reputation of this United Nations.
"And in particular, a stain on those who have failed to stand up to these atrocities and in some cases aided and abetted Assad's reign of terror."
Cameron pointed the finger at those, including Russia, who have blocked action in the Security Council, suggesting they have the blood of children on their hands.
Only by seeing the back of President Bashar al-Assad, can there be progress in Syria, he said.
The Prime Minister also paid tribute to the killed US ambassador Chris Stevens, calling his killing a "despicable act of terrorism".
He said: "The right response is to finish the work Chris Stevens gave his life to. And that's what the vast majority of Libyans want too."
Mr Cameron delivered the speech ahead of an appearance on the popular US talk show, the Late Show with David Letterman.