The Prime Minister called the killing of the US Ambassador to Libya, Chris Stevens, earlier this month 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."
The hands of the UN are stained with blood due to its failure to stop the Assad regime in Syria, David Cameron told the UN General Assembly.
David Cameron will urge the world to give support to the emerging democracies of the Arab Spring as he addresses the UN General Assembly.
President Obama said today that the US would not tolerate a nuclear-armed Iran, but that won't extinguish the heated Israeli rhetoric.