* Momentum is with opposition and Syrian people, U.S. says
* Long battle expected between pro-Assad, opposition forces
* But U.S. officials say defections are making a dent
WASHINGTON, Aug 6 (Reuters) - The White House said on Monday the defection of Syria's prime minister showed that President Bashar al-Assad's government was "crumbling from within" and repeated the U.S. call for him to step aside and end the violence gripping the country.
"This is a sign that Assad's grip on power is loosening. If he cannot maintain cohesion within his own inner circle, it reflects on his inability to maintain any following among the Syrian people that isn't brought about at the point of a gun," White House spokesman Jay Carney told a news briefing.
"The momentum is with the opposition and with the Syrian people. It's clear that these defections are reaching the highest levels of the Syrian government and Assad cannot restore his control over the country because the Syrian people will not allow it," he said.
The latest defection "only reinforces that the Assad regime is crumbling from within and that the Syrian people believe that Assad's days are numbered," Carney said.
In one of the highest-profile desertions from Damascus, Syrian Prime Minister Riyad Hijab on Monday fled the country. While not part of Assad's inner circle, his departure provides a powerful morale boost to the opposition.
Like the rebels, Hijab is from Syria's Sunni Muslim majority, while Assad is from the Alawite minority.
The United States has sought to increase pressure on Assad to leave power for more than a year.
U.S. intelligence officials expect pro-Assad and opposition forces to be in the fight for the long haul and are not predicting a near-term end to the Syrian conflict.
But U.S. officials say the defections are making a dent.
"It stands to reason that mounting defections are taking a psychological toll on the regime," a U.S. official said on condition of anonymity. "There's probably a range of motivations for why people are breaking with Assad, from self-preservation to an inability to tolerate his ruthless tactics."
"The impact of defections on regime stability will depend in part on the role these people play in the opposition," the official said. "And with the heat on the regime rising, Assad may be starting to wonder about the loyalty of some in his inner circle."
Former U.N. Secretary-General Kofi Annan announced last week he would resign his post as U.N.-Arab League Joint Special Envoy for Syria after Assad failed to respect the terms of a U.N.-backed peace deal and after China and Russia refused to support increased sanctions on Syria.
At the White House, Carney said the Obama administration would continue working with other countries and with Syria's opposition to keep pressure on Assad and encourage a peaceful political transition there.
09/09/2012 12:25 PM EDT
Syria Blasts Aleppo By Air
09/05/2012 7:50 AM EDT
Syrian City In Flames
08/25/2012 1:45 PM EDT
Lebanese Pilgrim Freed
Hussein Ali Omar, 60, one of 11 Lebanese Shiite pilgrims that Syrian rebels have been holding for three months in Syria, hugs his mother, right, upon arrival at his house in the southern suburb of Beirut, Lebanon, 2012. Syrian rebels freed Omar on Saturday in a move aimed at easing cross-border tensions after a wave of abductions of Syrian citizens in Lebanon. The Shiite pilgrims were abducted May 22 after crossing into Syria from Turkey on their way to Lebanon. (AP Photo/Hussein Malla)
08/24/2012 12:22 PM EDT
This image made from video and released by Shaam News Network and accessed Thursday, Aug. 23, 2012, purports to show the funeral of children in Daraya, near Damascus, Syria. Syrian troops backed by tanks and helicopters broke into a Damascus suburb on Thursday following two days of shelling and intense clashes as part of a widening offensive by President Bashar Assad's forces to seize control of parts of the capital and surrounding areas from rebel fighters, activists said. At least 15 people were killed in the offensive on Daraya, only a few miles (kilometers) southwest of Damascus. (AP Photo/Shaam News Network SNN via AP video)
08/24/2012 11:05 AM EDT
Lebanon Sees Heaviest Clashes In Months
Clashes between Assad supporters and opponents of the Syrian regime killed two people in Lebanon on Friday, the Associated Press reports. 17 people were injured.
The AP gives more context:
Syria was in virtual control of its smaller neighbor for many years, posting tens of thousands of troops in Lebanon, before withdrawing under pressure in 2005. Even without soldiers on the ground, Syria remains influential, and its civil war has stirred longstanding tensions that have lain under Lebanon's surface.
Read more on HuffPost World.
08/24/2012 11:02 AM EDT
A Sunni gunman fires a gun during clashes that erupted between pro and anti-Syrian regime gunmen in the northern port city of Tripoli, Lebanon, Friday, Aug. 24, 2012. The latest round of fighting first erupted on Monday in northern Lebanon and at least 15 have been killed in Tripoli this week and more than 100 have been wounded in fighting that is a spillover from Syria's civil war. (AP Photo/Hussein Malla)
08/24/2012 11:00 AM EDT
Refugee Numbers Soar
@ KenRoth :
UN reports 200,000 #Syria refugees, 30,000 in past week alone. Many more internally displaced not counted. http://t.co/BaM6u59j
08/23/2012 2:00 PM EDT
Syrian boy Musataf Alhafiz, 11, who fled his home with his family due to fighting between the Syrian army and the rebels, carries his brother Saif, 9 months, while he and others take refuge at the Bab Al-Salameh border crossing, in hopes of entering one of the refugee camps in Turkey, near the Syrian town of Azaz, Thursday, Aug. 23, 2012. Thousands of Syrians who have been displaced by the country's civil war are struggling to find safe shelter while shelling and airstrikes by government forces continue. (AP Photo/Muhammed Muheisen)
08/23/2012 12:09 PM EDT
Heaviest Bombardment This Month
Helicopter gunships shelled Damascus on Wednesday as Syrian security forces intensified their assault on the capital. Activists report that at least 47 people were killed.
"The whole of Damascus is shaking with the sound of shelling," a woman in the neighborhood of Kfar Souseh told Reuters.
Read more on HuffPost World.