The Syrian prime minister who defected says President Bashar al-Assad's government is on the verge of economic and moral collapse and controls no more than 30 percent of the country's territory.

Riad Hijab's comments came Tuesday in his first public appearance since he defected to the opposition earlier this month.

Meanwhile, U.S. Secretary of Defense Leon Panetta says he is confident the United States could enforce a no-fly zone over Syria, but that a “major decision” needed to authorize such a mission has not been made.

Panetta told the Associated Press the United States has planned for a number of possible events in Syria. He stressed that a no-fly zone is difficult to implement, and is not a top priority.

Foreign ministers of the 57-member Organization of Islamic Cooperation are holding a summit in Mecca Tuesday, after agreeing to recommend suspending Syria from the group. Syrian ally Iran says it will never accept the proposal.

Also Tuesday, the United Nations humanitarian chief Valerie Amos arrived in Syria to discuss ways to boost relief efforts to civilians caught up in the conflict. She is due to meet with Syrian government officials and the Syrian Red Crescent.

In China, the country's foreign minister is scheduled to hold talks with a special envoy to Syrian President Bashar al-Assad. China says it is also considering inviting opposition members to visit.

China has joined Russia in vetoing U.N. Security Council resolutions threatening Syria with sanctions for using heavy weapons against civilians.

Syrian rebels on Monday circulated video of what they claim is the downing of a Syrian plane and the captured pilot. The rebel video cannot be independently verified.

State media say a pilot ejected Monday after suffering technical problems during a “routine training mission” in eastern Syria, and that authorities are searching for him.