Various sources said chemical weapons may have been used by both parties to the conflict in Syria.
The BBC reported this week it has seen evidence Syrian forces dropped poisonous gas on civilian-populated areas last month. The Syrian government asked for a U.N. inspection, saying rebel forces deployed chemical weapons as well.
U.N. Secretary General Ban Ki-moon met in Moscow with Lavrov to discuss the crisis in Syria. The Russian government, a close ally of Syria, has expressed concern that international pressure over the crisis has so far been lopsided.
Ban said he was "deeply concerned" about the violence in Syria, adding an international conference aimed at finding a political solution to the crisis should get under way as soon as possible.
Lavrov said the Syrian government seems willing to let inspections proceed in the country once claims regarding Aleppo have been examined.
"We hope that agreements will be reached between the U.N. secretariat and the Syrian government," he was quoted by RIA Novosti as saying. "We are doing all we can to facilitate that."
Lavrov responded to allegations made in a New York Times article that Russian missiles were on their way to Syria. He said any arms deliveries take place under existing contracts and won't tip the balance in the regime's favor, the Russian report adds.