U.N. Special Envoy for Syria, Staffan de Mistura warned that miscalculations may occur, leading to an "unforeseen escalation". "They were behind the organization of those fabricated scenarios for the use of chemical weapons and now they are preparing such a development of the situation with the use of chemical weapons in Idlib", Muallem said.
Idlib has been a haven for rebels and their families evacuated out of areas won back by the government, but there is no obvious place for them to move to within Syria if they abandon the province now.
"We are striving to find an effective solution in the liberated Syrian north that would protect our people from a possible offensive by the criminal regime and its allies".
"We are conducting joint work with the Russians and Iranians on Idlib to avoid another Aleppo disaster", Erdoğan said during a Victory Day reception at the presidential palace in Ankara on August 30.
On April 14, the US, Britain and France carried out a string of airstrikes against Syria over a suspected chemical weapons attack against the city of Douma, located about 10 kilometers northeast of the capital Damascus.
After retaking a succession of rebel bastions around the country this year, the government of President Bashar al-Assad has set its sights on Idlib.
The UN estimates that a major Syrian government offensive in the Idlib area risks forcing another 700,000 Syrians from their homes. Turkey and the West fear a new humanitarian catastrophe and another wave of refugees into Europe as a result.
Russian Federation remains in discussions with its Astana Process partner Turkey - the guarantor of a de-escalation zone in Idlib - on how to avert a full-scale battle.
The Ustinov evidently cruised southward after its English Channel passage and eventually slipped through the Strait of Gibraltar before making what Russian news reports this week described as a "business call" at the port of Algiers.
The first phase of the offensive will include the town of Jisr al Shughour and the al Ghab plain on the western side of Idlib, and the towns of al Latamenah, Khan Sheikhoun and Maarat al Numan in its south, the Reuters source, said.
More than 350,000 people have been killed and millions displaced since Syria's war started in 2011 with the brutal repression of anti-government protests.
Taking those areas would bring Assad's regime close to regaining control over highways running from Aleppo to Hama and Latakia, two of Syria's most important pre-war roads. It has stepped up air strikes and shelling near the front lines, the Syrian Observatory for Human Rights has said. Since then, the regime has recaptured two-thirds of its territory with the help of Russian Federation.