In regaining control over other parts of Syria in the past year, Russian-brokered surrender deals offered safe passage for tens of thousands of rebels and their families to Idlib, which is why the province became the last bastion of the armed resistance.
There is "lots of evidence" that chemical weapons are being prepared by Syrian government forces in Idlib in northwest Syria, the new USA adviser for Syria said on Thursday, as he warned of the risks of an offensive on the country's last big rebel enclave.
"This means we are not in a hurry to pull out", said Ambassador Jim Jeffrey, the newly appointed U.S. special representative, noting that creating conditions in Syria where ISIS or another terrorist group can't return may take a while.
"Any offensive is to us objectionable as a reckless escalation", Jeffrey said.
"In the past 18 months I have stood on this floor twice, promising that the United States would respond to the use of chemical weapons in Syria", she said. Both Erdogan and Rouhani condemned the alleged USA support to rebel groups battling President Bashar al Assad's regime in a conflict that has claimed the lives of at least 5,00,000 people and displaced millions of Syrians, triggering a much larger migrant crisis impacting European nations across the Mediterranean.
What will happen to Syrian President Bashar al-Assad?
Idlib is one of the so-called "de-escalation" zones set up as a result of talks by Russia, Turkey and Iran a year ago as Damascus regained control of more of the country. The Turks are trying to find a way out. The attacks prompted terrified residents to flee before a fully-fledged assault gets under way, said the monitor. "The United States sends the ball into the corner of Russian Federation and Russia into the corner of the USA", he said.
Jeffrey said the U.S.is taking a tougher stance and will not tolerate an all-out attack on the region.
For the Syrian government and Russian Federation, the province is also strategically important because it borders Latakia Province, Assad's main stronghold and the site of Russia's biggest air base in the country as well as its naval facility.
Hossein Jaberi Ansari, a senior aide to Iran's foreign minister, told state TV on Thursday the final statement for the summit had already been "finalized" by senior representatives of the three countries.
Rouhani's criticism of the United States was echoed by Turkish President Erdogan who stated that Turkey is "deeply annoyed by U.S. supporting a terrorist organisation in Syria".
In the statement, Rouhani, Putin and Erdogan "reaffirmed their determination to continue cooperation in order to ultimately eliminate Daesh/ISIL, al-Nusra Front and all other individuals, groups, undertakings and entities associated with al-Qaeda or Daesh/ISIL, as they have been designated as terrorists by the UN Security Council". The Iranian president repeatedly stressed that foreign influence was a major factor in escalating the war in Syria, and called on the USA to withdraw the troops that it has illegally deployed in Syria.
France has invited the United States, Jordan, Egypt, Saudi Arabia, Germany and Britain for talks on the sidelines of the UN meeting to discuss Syria, Jeffrey said.
"Assad has no future, but it's not our job to get rid of him", said Jeffrey.