Assad's troops have yet to employ chemical weapons as part of their violent crackdown on anti-govemment rebels in the country.
"The arsenal, based on reports, is quite alarming," Ahmet Uzumcu, head of the Organisation for the Prohibition of Chemical Weapons (OPCW), told Reuters on Wednesday.
"If those reports are correct it would really take a lot of resources and efforts to destroy, to eliminate, those stocks," Uzumcu said.
Syria is one of eight nations that did not sign onto the Chemical Weapons Conventions in 1997. The country's refusal to sign onto that pact means international weapons inspectors have no jurisdiction to track Syria's stockpiles.
Concerns over those weapons and Assad's possible willingness to use them on Syrian civilians has become a key issue in the ongoing debate inside the Pentagon and on Capitol Hill on the impact of regime change in Syria.
Sen. Jeanne Shaheen Jeanne ShaheenOvernight Finance: Senators spar over Wall Street at SEC pick's hearing | New CBO score for ObamaCare bill | Agency signs off on Trump DC hotel lease Senators demand Pentagon action after nude photo scandal Senate Dems: We won't help pass additional health bills MORE (D-N.H.) pressed Central Command chief Gen. James Mattis on the issue of Syria's chemical weapon stockpiles during a March 6 Senate Armed Services Committee hearing.
“What happens if those weapons are left unsecured — could they potentially disappear and be used throughout the region?” Shaheen asked Mattis at the hearing. “Is there any suggestion that Assad might actually use these weapons against the people of Syria?”
Mattis said it was unlikely that Assad would use those weapons on his own people.
But if those weapons remain unchecked if and when the regime falls, the chance they could fall into the hands of groups like al Qaeda is "potentially a very serious threat."
Last October, U.S. intelligence allegedly picked up "worrying indicators" that a number of shoulder-fired rockets stockpiled by Libya had been smuggled out of the country after rebels toppled the regime of former Libyan dictator Moammar Gadhafi.
The missiles, similar to the famous Stinger anti-aircraft missile that the United States supplied to the Afghans to defeat the Soviets, might have been shipped to Islamic terror groups operating in the region, Africa Command chief Gen. Carter Ham said at the time.
American military and intelligence officials claim al Qaeda elements have already infiltrated the ranks of the Free Syria Army, the top anti-government group battling Assad's forces.
The issue of al Qaeda influence within the Syrian resistance is one of many scenarios American and NATO leaders considered when discussing the possible political and military fallout in Syria if Western powers decide to remove Assad.
U.S. and alliance leaders essentially "want to know what [comes] next, before taking that step [to] military action," Chairman of the Joint Chiefs of Staff Gen. Martin Dempsey said Tuesday regarding last April's NATO talks.
Despite those ongoing discussions, Dempsey made clear there was nothing the United States or NATO could do to guarantee any political outcome in a post-Assad Syria, if military action is taken.