WASHINGTON - The emir of Qatar has said he is in favour of sending Arab troops to Syria to "stop the killing" that has claimed more than 5,000 lives over the course of a 10-month revolt there.

Sheikh Hamad bin Khalifa al-Thani's interview with CBS news program "60 Minutes," which airs Sunday, is the first public call by an Arab leader for Arab troops to deploy to Syria, where President Bashar al-Assad's regime has mounted a brutal crackdown. When asked whether he favours Arab nations intervening in Syria, the emir said: "For such a situation to stop the killing... some troops should go to stop the killing."

The interview with the Qatari leader, excerpts of which were sent to AFP by CBS ahead of the broadcast, comes amid increasing concern that a team of Arab observers to Syria to monitor conditions on the ground was failing, and as Arab League chief Nabil al-Arabi warned that the mission could be suspended.

The influential emir once had cordial relations with Damascus, but in recent months has become one of the most vocal critics of the Assad regime in the Arab world as the Syrian strongman failed to curb the bloodshed. In August, Sheikh Hamad described the Syrian regime's heavy-handed use of force against protesters as "fruitless," and urged serious reforms. The wealthy Gulf state then withdrew its ambassador from Damascus. Doha-based Al-Jazeera television has come under strong criticism by the Syrian authorities for its coverage of the popular uprising.

A top Syrian army defector was set to take charge of the rebel army's operations on Saturday, as the United States accused Iran of supplying munitions to aid Damascus' bloody crackdown on protests.

Washington has reason to believe Iran is supplying security-related equipment "including munitions" to Syrian forces, a US official said late on Friday, after the head of the elite Revolutionary Guards' Quds force, Qasem Soleimani, visited Damascus earlier this month.

The accusations came after Britain sharply criticised Russia for refusing to support UN Security Council moves against President Bashar al-Assad.

British Prime Minister David Cameron said during a visit to Saudi Arabia that vetoing a Security Council resolution against Damascus amounted to standing by and watching the "appalling bloodshed."

In October, Russia and China vetoed a Western draft resolution that would have condemned the Assad regime. Russia later circulated an alternative that would have pointed the finger at both sides.  Cameron told Al-Arabiya television on Friday that Britain stands ready to take a fresh resolution on Syria to the Security Council. He said it would dare "others that if they want to veto that resolution to try to explain why they are willing to stand by and watch such appalling bloodshed by someone who has turned into such an appalling dictator." Referring to the alleged Iranian aid to the crackdown by its Syrian ally, an official in Washington said the United States has reason to believe that Iran is supplying security-related equipment "including munitions" to Syrian forces.

The United States has long suspected that Iran has been aiding Syria's purge as Assad clings to power and tries to avoid the fate of other Arab dictators felled by the Arab Spring uprisings.

Another official said Soleimani's visit marks the strongest indication yet of direct cooperation between the allies. Efforts to isolate the Syrian government were boosted by rebel plans to form a high military council headed by a top Syrian army defector that will oversee military operations against President Bashar al-Assad's embattled regime.

General Mustafa Ahmad al-Sheikh, the most senior commander to defect from the Syrian army, will announce the council's formation later on Saturday in Turkey, where he sought refuge 12 days ago, his media advisor said. Sheikh, 54, was in charge of security in northern Syria before defecting. In a statement, he said he had deserted because he was sickened by the ruthlessness of Assad's regime and all the killings taking place. "This council, headed by Sheikh, will oversee military operations in conjunction with the Free Syrian Army," Fahad Almasri told AFP, and will include high-ranking officers who will plan operations to be executed by the FSA.