Russian Federation said the gas was part of rebel stockpiles, which the rebels have denied.
On Thursday, Moscow hosted Syrian Foreign Minister Walid Muallem for talks with Lavrov, ahead of a three-way meeting Friday with Foreign Minister Mohammad Javad Zarif of Iran, another Assad ally.
"Our impression is that the West, mainly the United States, is hand-in-glove with the terrorists".
At the time, the Syrian government rejected the accusations, blaming the rebels of storing chemical materials in the targeted area.
Assad insisted his forces had turned over all their chemical weapons stocks years ago and would never use the banned arms.
It was the deadliest such incident since a sarin gas attack killed hundreds of people in a rebel-held suburb of Damascus in 2013, prompting threats of US military action.
Syria and Russian Federation have suggested a conventional airstrike by the Syrian army may have hit a depot storing chemical weapons possessed by extremists.
But Assad said evidence came only from "a branch of Al- Qaeda", referring to a former jihadist affiliate that is among the groups that control Idlib province, where Khan Sheikhun is located.
Champions League: Griezmann stars as Atletico Madrid outplay Leicester City
Atletico played a deep line to nullify Jamie Vardy's threat after boss Diego Simeone pinpointed him as the main danger before the game.
Asked if he had ordered the chemical weapons attack, Assad said the Syrian military had no chemical weapons and that it would not use them if it did. Moscow has claimed it was the rebels responsible for whatever chemical agent was found in Syria.
He said: "It's not clear whether it happened or not, how can you verify a video?"
The Kremlin in a statement confirmed that Putin and Erdogan had spoken "in favor of conducting an objective and full global investigation as soon as possible". The organization has not revealed any details, citing the need to preserve the integrity of the probe and the safety of OPCW staff.
Moscow has warned against putting the blame on Damascus until an independent inquiry is conducted and vetoed a proposed United Nations resolution on the attack, saying it failed to mention the need to inspect the affected area.
"The strike was requested by the partnered forces, who had identified the target location as a Daesh fighting position", it said in a statement.
"If Russia continues to obstruct the Security Council from passing resolutions to protect the Syrian people, the United States must build a broad coalition to place diplomatic pressure and, where feasible, economic sanctions, on Russia to persuade it to lift its veto and protect Syrian civilians", added Hicks.
U.S. Central Command said Thursday that coalition aircraft were given the wrong coordinates by their partner forces, the predominantly-Kurdish Syrian Democratic Forces, for a strike meant to target Islamic State militants south of their Tabqa stronghold.
Comments