President Bashar Assad pledged in an interview broadcast Monday to honor an agreement to surrender Syria’s stockpile of chemical weapons, but he said that rebels might try to block international arms inspectors from doing their work.

As battles continued across Syria, new video of an attack Sunday night showed the regime’s helicopters dropping barrel bombs on opposition-held areas, creating chaotic scenes of destruction.

In a sign of worsening infighting among the rebels, a top al-Qaida commander in Syria was killed in an ambush by rival, Western-backed group — an assassination sure to raise tensions among factions seeking to topple the regime.

Assad’s comments came as world leaders gathered in New York for the annual U.N. General Assembly, where the use of chemical weapons in Syria’s civil war was high on the agenda.

The Syrian leader told Chinese state TV that Damascus is dedicated to implementing the agreement reached between Russia and the U.S. to surrender its chemical weapons to international control. Syria’s stockpile, he said, is “in safe areas and locations and under the full control of the Syrian Arab Army.”

Assad cautioned, however, that the rebels might block inspectors from reaching some of the locations, in order to frame the government.

“I’m referring to places where gunmen exist. Those gunmen might want to stop the experts’ arrival,” Assad told CCTV in the interview, which was shot Sunday in Damascus and broadcast Monday.

Under the agreement brokered Sept. 14 in Geneva, inspectors are to be in Syria by November and all components of the chemical weapons program are to be removed from the country or destroyed by the middle of next year.

The revelations of Syria’s chemical weapons arsenal became public after an Aug. 21 attack near Damascus that a U.N. report found included the use of the nerve agent sarin. Hundreds of people died in the attack that brought Washington to the brink of military intervention before the accord was struck between the U.S. and Russia.

The U.N. inspectors face enormous challenges, including maneuvering between rebel- and government-controlled territory. Last month, snipers opened fire on a U.N. convoy carrying a team on its way to investigate the Aug. 21 incident.

Opposition fighters have insisted they will also cooperate with any inspectors or experts who come to Syria.

Ralf Trapp, a former chemical arms inspector who is now a disarmament consultant, said Assad was legally obligated to let in inspectors under the chemical weapons treaty. But, he cautioned, “they can use the security situation as an excuse. They can delay things.”

Damascus met a first deadline under the Geneva agreement, submitting last week what was supposedly the full list of its chemical weapons and production facilities to the Organization for the Prohibition of Chemical Weapons so they can be secured and destroyed.

Also Monday, Hezbollah leader Sheik Hassan Nasrallah categorically denied rebel claims that his group had received chemical weapons from Syria.

The U.S.-Russian deal has dealt a blow to the rebels, who had hoped a U.S.-led military strike would turn the war in their favor. Opposition leaders have warned the regime will continue to wield conventional weapons in the civil war, which has killed more than 100,000 people since the uprising began in March 2011.

Fierce fighting between regime forces and rebels Monday included an airstrike that killed at least six people from the same family in central Hama province.