"The Syrian army is being stretched to the maximum because of simultaneous crackdowns on rebel holdouts across Syria," said the official, who asked that his name and country not be used because he is not authorized to speak publicly.
Citing regional intelligence data, the official also said jammed Internet, satellite and cellphone circuits across Syria are contributing to the military's woes, mainly by depriving army commanders of the means to communicate with field officers. He said the circuits are believed to have been jammed by Russian telecommunications equipment, installed in the early summer to block rebel communications.
With the regime hurting but still strong, the opposition would need an influx of weapons quickly to tip the balance of the conflict.
The rebels' desire for arms was clear last week at an opposition conference in Qatar.
"Weapons," barked George Sabra, a Syrian opposition figure, as rebels gathered for a unity conference with envoys from Washington and its Middle East allies in attendance. "We don't need food. We don't need money. We need weapons."
The appeal came just hours before Syria's splintered rebel factions agreed Sunday to an American-backed plan to unite under a new umbrella group that seeks a common voice and strategy against Assad's regime.
Now, outgunned rebel fighters are waiting to see whether the pledge of cooperation will be rewarded with potentially game-changing arms — including critical anti-aircraft batteries — from main regional backers such as the wealthy Gulf states and Turkey.
A big part of the decision likely rests with the U.S., which has so far discouraged opening channels for heavy weapons because of unease about squabbling among Syrian rebels and possible footholds by Islamic extremists among the fighters.
The Obama administration has steered clear of any pledges to directly arm rebels. But some opposition figures believe Washington could give its tacit support to others funneling weapons if the new broad-based rebel coalition holds together and gains international legitimacy, such as winning recognition from the Arab League and other groups