United States Defense Secretary Chuck Hagel said Thursday that his country would continue to support "moderate" rebel forces in Syria, but will withhold non-lethal assistance to the rebels until it can assess who is in control of arms depots and border crossings.
According to AFP, Hagel told reporters that setbacks for Syria's Western-backed opposition are a "big problem" and the United States is assessing the damage.
"I think what has occurred here in the last couple of days is a clear reflection on how complicated and dangerous this situation is and how unpredictable it is," Hagel said at a joint press conference with Singapore's defense minister.
The comments came a day after the United States and Britain both announced that they have rescinded funding for Syrian rebel groups. This was done because more extreme Islamist groups took over a base run by the Western-backed groups.
According to AFP, a powerful rebel faction, the Islamic Front, last week seized the Bab al-Hawa crossing on the Turkish border and weapons warehouses from the Free Syrian Army, which is led by General Selim Idriss.
A U.S. official confirmed to the news agency that the Islamic Front seized a compound near the Turkish border belonging to the Free Syrian Army, or the Supreme Military Council (SMC).
"Following that, SMC officials fled other compounds out of fear that they could be attacked as well," said the official, who spoke on condition of anonymity.
"The initial incident occurred at a single compound but there were ripple effects," the official said.
Some media reports claimed Idriss had fled Syria, but a spokesman said he was on a working trip to Turkey.
"We continue to support General Idriss and the moderate opposition," Hagel said.
"But this is a problem, I mean, what has occurred here, a big problem. And we're going to have to work through it and manage through it with General Idriss and the moderate opposition," he added, according to AFP.
Asked who was in control of the arms depots, Hagel said, "We're evaluating right now. We're assessing what has happened, where we are."
He said there were "very dangerous elements" in the opposition that "complicates our support" for the rebels.
Delivery of non-lethal assistance would be withheld "until, first of all, we can get a clear assessment of what has happened," Hagel said.
The West has been weary of arming the Syrian rebels because of the presence of jihadist groups among them, such as the Al-Nusra Front, which has pledged allegiance to Al-Qaeda chief Ayman al-Zawahiri.
Al-Nusra is one of 13 factions in the radical Islamist rebel council that announced its secession from the main opposition force and declared its own Islamic state in Aleppo. Members of the group have performed atrocities during the ongoing civil war, including publicly beheading a Catholic priest who was accused of collaborating with the Assad regime.