The presidents of Iran and Russia backed a military offensive to retake the last zone controlled by Syrian rebels, while the president of Turkey called for a ceasefire that may be the last chance to avoid what activists warn will be a humanitarian disaster.
A trilateral summit in Tehran between Iranian President Hassan Rouhani, Russian President Vladimir Putin and Turkish President Recep Tayyip Erdogan was seen as an opportunity for a diplomatic solution before unleashing a full-scale assault on the northwestern province of Idlib in Syria .
Instead, Friday's summit further underscored the marked differences between the allies of convenience in the seven-year war in Syria, the subject of a summit that did not directly represent embattled President Bashar Assad.
Putin pushed for a muscular military response to crush the rebel fighters in Idlib, calling at one point the "total annihilation of terrorists in Syria."
Rouhani focused on the reconstruction and the need for the displaced Syrians to return to their homes, while calling for the United States to withdraw immediately.
"The fires of war and bloodshed in Syria are coming to an end," Rouhani said, adding that terrorism must be "uprooted in Syria, particularly in Idlib."
Erdogan may have been the leader with more to lose before the offensive.
Turkey, which backed opposition forces against Assad, fears an avalanche of refugees fleeing a military offensive and the destabilization of areas it now has in Syria.
"Idlib is not only important for the future of Syria, it is important for our national security and for the future of the region," Erdogan said.
"Any attack on Idlib would result in a catastrophe, any fight against terrorists requires methods based on time and patience."
"We do not want Idlib to become a bloodbath," he added.
The province of Northwestern Idlib and its environs are home to some 3 million people, of whom almost half are civilians displaced from other parts of Syria.
That also includes an estimated 10,000 unconditional fighters, including militants linked to al Qaeda.
Responding to Erdogan's proposal for a ceasefire in Idlib, Putin said that "a ceasefire would be good," but indicated that Moscow does not believe it will be maintained.
There was no immediate reaction from the fighters in Idlib.
Early on Friday, a series of air strikes hit villages in the southwest of Idlib, targeting insurgent posts and killing a combatant, said the head of the Syrian Human Rights Observatory based in Britain, Rami Abdurrahman.
Abdurrahman said the suspicious Russian warplanes carried out the attack.
The United States ambassador to the United Nations, Nikki Haley, warned that any military offensive in Idlib "would be a reckless escalation."
The UN envoy to Syria says that any proposal to prevent Idlib from becoming "the greatest humanitarian tragedy at the end of the most horrible recent conflict in our memory" should have an opportunity.
Staffan De Mistura also called for "protected voluntary evacuation routes" for civilians if they want to leave Idlib.