UNITED NATIONS: The emir of Qatar on Tuesday called for an Arab intervention force to be sent to Syria to halt the escalating conflict.
Sheikh Hamad bin Khalifa Al-Thani, a key backer of the Syrian opposition, made the call at the UN General Assembly after UN leader Ban Ki-moon said the conflict had become "calamity" that threatens global peace.
US President Barack Obama called for the international community to join together to end the rule of President Bashar al-Assad.
Because of the failure of international efforts to end the war "it is better for Arab countries themselves to intervene out of their humanitarian, political and military duties and do what is necessary to stop the bloodshed," al-Thani told the General Assembly.
The emir cited the precedent of an Arab intervention force sent to Lebanon in the 1970s in a bid to halt that country's civil war. He called the Arab League-backed operation in 1976 "a step that proved to be effective and useful."
The Qatar leader is a fierce critic of Assad whose government has accused Qatar and Saudi Arabia of arming Syrian rebels.
Al-Thani said the 18-month old Syrian conflict "has reached an unacceptable phase" with a government "that does not hesitate to use all sorts of weapons against its people."
He said intervention was needed because all efforts to "get Syria out of the cycle of killing" had been in vain and the UN Security Council has "failed" to take a stand.
Condemnations of Assad marked the opening day of the UN General Assembly of world leaders, as the conflict passes 18 months and the international community remains deadlocked over how to end the bloodshed.
The conflict "is a regional calamity with global ramifications" that needs action by the Security Council, Ban said as he opened the summit.
"The international community should not look the other way as violence spirals out of control," Ban told world leaders, adding that "brutal" rights abuses were being committed by Assad's forces.
He said the Security Council and countries in the region must "solidly and concretely" support peace efforts by UN-Arab League envoy Lakhdar Brahimi.
"We must stop the violence and flow of arms to both sides and set in motion a Syrian-led transition as soon as possible," Ban added.
The 15-nation Security Council is deadlocked over the conflict which Syrian activists say has left more than 29,000 dead.
Russia, Assad's main ally, and China have vetoed three Security Council resolutions which could have led to sanctions against the Syrian government.
Obama said there had to be "sanctions and consequences" for atrocities committed in the war and that Assad must go. He also said that Iran "props up a dictator in Damascus."
"The future must not belong to a dictator who massacres his people," Obama told the assembly.
"If there is a cause that cries out for protest in the world today, it is a regime that tortures children and shoots rockets at apartment buildings."
He told leaders: "As we meet here, 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."
Obama also warned that the international community must stop the uprising against Assad turning into "a cycle of sectarian violence."
He said the United States wants a Syria "that is united and inclusive; where children don't need to fear their own government, and all Syrians have a say in how they are governed -- Sunnis and Alawites; Kurds and Christians."
"That is the outcome that we will work for -- with sanctions and consequences for those who persecute; and assistance and support for those who work for this common good," Obama said.
Brazil's President Dilma Rousseff, whose country hesitated over action against Assad when it was on the UN Security Council, said the Syrian government "bears the largest share of responsibility" for the violence.
But she also highlighted the role of opposition groups "especially those that increasingly rely on foreign military and logistical support."