Video protests are attack on freedom, warns Barack Obama

President Barack Obama challenged global leaders at the United Nations last night to "seize the moment" to repel the forces of extremism and violence and to defend tolerance and freedom, declaring that nations "face a choice between the forces that would drive us apart and the hopes we hold in common".

While he used his last major speech on the world stage before the US elections to serve notice to Iran that time was running out for it to renounce nuclear arms and again to call for the removal of Syria's President, Bashar al-Assad, Mr Obama chose to focus his remarks on recent turmoil in the Middle East ignited by a US-made video insulting Islam.

"The attacks of the last two weeks are not simply an assault on America," the President said after paying tribute to Chris Stevens, the US ambassador who was killed in Libya. "They are also an assault on the very ideals upon which the United Nations was founded – the notion that people can resolve their differences peacefully; that diplomacy can take the place of war."

While repeating that the US government had nothing to do with the video, Mr Obama underscored America's attachment to freedom of speech. "I accept that people are going to call me awful things every day, and I will always defend their right to do so," he said, briefly striking a personal tone. "Americans have fought and died around the globe to protect the right of all people to express their views."

But violence is never the answer to offence, he insisted. "There are no words that excuse the killing of innocents. There is no video that justifies an attack on an embassy. There is no slander that provides an excuse for people to burn a restaurant in Lebanon, or destroy a school in Tunis, or cause death and destruction in Pakistan."

Moreover, it is not just the US that is threatened, the President warned. "The impulse towards intolerance and violence may initially be focused on the West, but over time it cannot be contained," he said. "The same impulses toward extremism are used to justify war between Sunnis and Shia, between tribes and clans."

The mood here has been rendered sombre not just by the eruptions of violence of the past few weeks but also the war in Syria and the tension between Israel and Iran, issues that threaten to overshadow other business, including a meeting last night on the UN Millennium Development Goals co-chaired by David Cameron.

Mr Cameron, who will leave New York for Brazil today, insisted last night that even during times of economic austerity, it is important to remain faithful to the UN overseas aid goals. "I think its important that countries keep promises made to the poorest people in the world," he said.

Ahead of a meeting this morning between Mr Cameron and Egypt's new president, Mohammed Morsi, Downing Street last night said that Britain will resume giving military advice to the country to help it combat extremism and ensure stability in the region. As part of the initiative, the UK will send its top general, Sir David Richards, the Chief of the Defence Staff, to Cairo to lead a stabilisation team in collaboration with the new government.

Ban Ki-moon, the UN Secretary General, implored delegates to take action to stop the civil war in Syria, saying it was "a regional calamity with global ramifications". He also castigated Israel for "shrill war talk" towards Iran which had become "alarming".

On Iran, Mr Obama said containing a nuclear Iran could not be an option. An Iran with a nuclear arsenal would "threaten the elimination of Israel, the security of Gulf nations, and the stability of the global economy," he said. "And that is why the United States will do what we must to prevent Iran from obtaining a nuclear weapon."

The President drew no new red line on Iran, however, sticking with the established policy of sanctions. Familiar also was his call for a transition in Syria: "We again declare that the regime of Bashar al-Assad must come to an end so that the suffering of the Syrian people can stop, and a new dawn can begin."

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