"All we've seen are the actions of cowards interested in a bloody military conquest of Idlib".
Since then, more than a quarter of a million people have been killed and more than 10 million displaced across the war-battered country, according to United Nations figures.
"Idlib province is ... a sort of zone of responsibility of Turkey; it is their responsibility to separate the moderate opposition from the extremists, from Jabhat al-Nusra and other groups, other terrorist groups", he said.
Turkey, Russia and Iran a year ago set up the Astana process, a negotiating track to end Syria's war that complements the UN-led peace process. Besides, there is also a list containing the names of civil activists.
Turkey's Sinirlioglu, whose country supports the Syrian opposition, countered that "only a viable cease-fire would allow the creation of an environment to effectively fight terrorism".
"The United States is long past taking Russian Federation and Iran at their word that they are genuinely interested in protecting civilians in Idlib from further violence", Haley said.
Guterres said he understands that "the present situation in Idlib is not sustainable and the presence of terrorist groups can not be tolerated".
"An operation would result in a massacre", Erdogan says. "But fighting terrorism does not absolve warring parties of their core obligations under worldwide law", he said.
"If Assad, Russia, and Iran continue down the path they are on, the consequences will be dire".
Russian Federation is due to brief the United Nations Security Council later Tuesday about the results of the Tehran summit it held with Iran and Turkey on the fate of Syria's Idlib province.
At the summit in Tehran, Erdogan, Russia's Vladimir Putin and Iran's Hassan Rouhani agreed in a statement that there could be no military solution to the conflict and it could only end through a negotiated political process.
USA national security adviser John Bolton said the United States, Britain and France agreed Syria would be met with a "much stronger response" compared with previous air strikes if its government conducted another chemical weapon attack, The Guardian reported.
More than 3 million people live in the rebel-held territory, almost half of them already displaced from fighting elsewhere in Syria.
Russia's Nebenzia responded saying attempts to separate the three Astana guarantors "will not be successful".