The United Nations Security Council will hold a meeting on Friday on the situation in Syria's Idlib province, U.S. Ambassador to the U.N. Nikki Haley said on Tuesday, warning Syria's government not to use chemical weapons ahead of a widely expected military offensive there.
Meanwhile, Russian and Syrian planes pounded areas on the western edge of Idlib, the last major rebel stronghold, on Tuesday, according to the Syrian Observatory for Human Rights and a rebel source, adding that 13 civilians but no fighters were killed in the strikes.
A Syrian government minister said the siege of Idlib would probably be resolved by force.
"Until now, military action is more likely than reconciliations," Reconciliation Minister Ali Haidar told Russia's Sputnik news agency.
Damascus uses the term "reconciliation" for the negotiated rebel surrenders that have taken place in some areas.
"Idlib is different from other regions because of the large numbers of fighters," Haidar said. "However, we cannot say there is no gateway to reconciliation."
"This is a tragic situation, and if they want to continue to go the route of taking over Syria, they can do that," Haley said at a news conference, referring to Syrian President Bashar Assad's government as well as its allies Russia and Iran.
"But they cannot do it with chemical weapons. They can't do it assaulting their people and we're not going to fall for it," she added.
The world's chemical weapons watchdog has documented the systematic use of banned munitions in Syria's civil war, including nerve agent sarin and sulfur mustard gas. But the body, the Organization for the Prohibition of Chemical Weapons, has not assigned blame for the attacks.
"If there are chemical weapons that are used, we know exactly who's going to use them," Haley said.
White House spokeswoman Sarah Sanders said the U.S. is closely monitoring the situation in Idlib province, where it is feared that a Syrian government offensive could spark a humanitarian disaster.
She echoed Haley's warning, saying the United States and its allies would respond "swiftly and appropriately" if Assad used chemical weapons again.
Sanders said the U.S. will work with its allies to find a lasting diplomatic solution to resolve the hostilities in Syria under the auspices of U.N. Security Council Resolution 2254.
U.S. President Donald Trump in the past year and a half has twice ordered U.S.-led air strikes against targets in Syria in response to what Washington called the Assad government's use of chemical weapons against civilians.
In a tweet on Monday, Trump warned Assad and his allies Iran and Russia not to "recklessly attack" Idlib province and warned that hundreds of thousands of people could be killed.
The Kremlin on Tuesday dismissed Trump's warning to Syria not to launch an offensive in Idlib, saying the area was a "nest of terrorism."
The northern province and surrounding areas are the last major enclave held by insurgents fighting Assad. Half of Idlib's 3 million people have already fled there from their homes in other parts of Syria, according to the U.N., and any offensive threatens new displacement and human misery.
It could also spark a wider confrontation with Turkey, a supporter of the rebels, whose army has set up observation posts along the Idlib front lines to deter fighting.
Turkey's Hurriyet daily reported that Turkish armed forces were reinforcing the Idlib border with M60 tanks, and Reuters television filmed a convoy heading toward the border.
Iran's Deputy Foreign Minister Abbas Araqchi said, "Terrorist groups [in Idlib] have mixed with the people. They are using people as human shields."
Idlib's dominant rebel faction is Tahrir al-Sham, an alliance spearheaded by al-Qaida's former official affiliate in Syria, the Nusra Front, though other groups are also present.
Last week the U.N. envoy to Syria, Staffan de Mistura, said the Nusra Front and al-Qaida, both of which the international body designates as terrorists, had an estimated 10,000 fighters in Idlib.
On Tuesday de Mistura said talks between Russia and Turkey held the key to resolving the fate of Idlib without a bloodbath. He said he had heard reports that Damascus had set a Sept. 10 deadline for diplomacy to work before attacking.
Turkish President Recep Tayyip Erdogan warned Tuesday that an attack on Idlib would be "a massacre."
"The situation in Idlib is crucial for Turkey. A ruthless process has been going on there. … God forbid, if this area is hailed by missiles there would be a serious massacre," he said.
Turkish Foreign Minister Mevlut Cavusoglu said Turkey was discussing joint action with Russia to target terrorist groups in Idlib while avoiding a full-scale offensive. Ankara last week added Tahrir al-Sham to its list of designated terrorist groups.
Last week a source close to Damascus said the government was preparing a phased assault that would initially target the areas in the south and west of the rebel enclave.
Even a staggered offensive would involve fighting around Turkish observation posts, potentially triggering a new escalation in an already complex war.
