Former Syrian Prime Minister Riyad Hijab, who defected to Jordan last week, has said that President Bashar al-Assad's regime controls only 30 percent of the country.
Hijab, who on August 14 made his first public appearance since fleeing Syria, said Assad's regime was collapsing "morally, financially, and militarily."
"I assure you, through my experience and the position I used to fill, that the regime is collapsing psychologically, financially, and economically with cracks in its military power," he said. "It is only in control of 30 percent of Syrian land."
He called the regime "enemies of God" and called on government troops and officials to join the rebel side.
"I am reminding you of your oath when you were enlisted in the army," he said. "Why will you point your guns -- to protect your people or to kill them? I am certain you will side with your people, preserve your holy places, its soil, and the blood of its people."
Hijab, a Sunni Muslim, was not in Assad's inner circle but is the most senior civilian official to have defected thus far.
The United States on August 14 lifted sanctions against Hijab, unfreezing his assets as it urged more individuals to abandon Assad's regime.
In Washington, U.S. State Department spokesperson Victoria Nuland said the move does not mean that Hijab won't be held accountable in the future for his actions while part of the regime.
"This issue doesn't affect the question of what the Syrian people may or may not decide with regard to accountability for former regime officials," Nuland said. "This designation in the first place was part of our larger sanctions policy vis-a-vis Syria, which is designed to squeeze the regime individually [and] collectively and dry up the money that it uses to perpetrate its crimes."
Meanwhile, UN humanitarian aid chief Valerie Amos has arrived in Damascus to discuss the "deteriorating humanitarian situation" for civilians trapped or displaced by fighting.
Amos was due to meet with government officials and representatives of the local Red Crescent.
The UN's Office for the Coordination of Humanitarian Affairs said Amos's trip aimed to "draw attention to the deteriorating humanitarian situation in Syria" and the impact on civilians.
An estimated 2 million Syrian civilians have now been affected by the crisis and more than 1 million have fled their homes, while tens of thousands of people have fled into neighboring countries.
The UN says there are more than 150,000 Syrian refugees in neighboring countries, but many believe the number is several times higher.
Meanwhile, Bouthaina Shaaban, the Syrian president's special envoy, was in China on August 14 to meet with Foreign Minister Yang Jiechi.
The Chinese Foreign Ministry said the meeting was part of Beijing's efforts to "promote a political solution" to the conflict in Syria.
The ministry also said it was considering inviting opposition figures to hold more talks in Beijing.
China, along with Russia, has vetoed UN Security Council resolutions against Assad’s regime.
OIC Considers Syria Ban
In another development, Syria is facing suspension from the Organization of Islamic Cooperation (OIC) because of its handling of the crisis.
A draft resolution, backed by foreign ministers, is to be submitted at a two-day OIC summit in the Saudi Red Sea city of Jeddah starting on August 14.
The AFP news agency reported that only foreign ministers from Algeria and Iran, which is regarded as Syria's closest ally, were against the recommendation.
In Syria, state media reported that Syrian armed forces in the central province of Homs had killed a large number of "mercenary terrorists" on August 13, while opposition groups said rebels had clashed with government forces in the northern city of Aleppo and the capital, Damascus.
The rebels also produced footage of a man they claim was the captured pilot of a fighter jet shot down in the country's east.
But state media said the plane crashed because of "technical problems" and a search was under way to find the pilot.