UNITED NATIONS (AP) -- The U.N. Security Council will vote Saturday on rival Syria resolutions sponsored by France and Russia and both are virtually certain to be vetoed, leaving the war-ravaged country and the besieged city of Aleppo engulfed in conflict and key powers deeply divided.
Russia's last minute introduction of a rival resolution on Friday afternoon took Western supporters of the French draft by surprise.
Several diplomats privately called it a brilliant move by Moscow because it will force Western powers to veto as well.
So instead of Russia alone being put in a negative spotlight for vetoing the French resolution demanding an end to the bombing campaign by Syrian and Russian aircraft in Aleppo, the Western powers are highly likely to veto the Russian draft because it makes no mention of a bombing halt.
As a result, the votes Saturday afternoon, first on the French draft and then on the Russian proposal, are expected to exacerbate tensions between Moscow and the West over the Syrian conflict that has raged for more than five years, killing over 300,000 people.
Since the collapse of the U.S.-Russia-brokered cease-fire two weeks ago, the situation in Syria has dramatically deteriorated, with both countries escalating their rhetoric and actions.
Russia's military warned the U.S. on Thursday against striking the Syrian army, stressing that Russian air defense weapons in Syria stand ready to fend off any attack.
U.S. Secretary of State John Kerry stepped up the West's attack Friday morning, calling for Russian and Syrian military strikes against civilians and medical facilities in Syria to be investigated as war crimes.
France circulated its draft resolution a week ago, saying it wanted the council to unite behind it. But negotiations never got Russia on board and French Foreign Minister Jean-Marc Ayrault's visit to Moscow this week didn't either.
Russia, a close Syria ally, has opposed any grounding of its warplanes, which have been supporting President Bashar Assad's military campaign.
Russia's U.N. Ambassador Vitaly Churkin called the French draft, which demands an immediate end to all bombing and military flights over Aleppo, "very hastily put together."
"I frankly believe that this is designed not to make progress" in ending the current stalemate "but to cause a Russian veto," he told reporters after U.N. envoy Staffan de Mistura briefed the Security Council behind closed doors on Friday morning.
Churkin, the current council president, said it was "unprecedented" that the 15-member council would ask a permanent member to limit its activities, in this case requiring the Russian military to stop flights.
Asked if Russia would veto the French draft, Churkin said he never uses the word until he gets instructions from Moscow, but "I cannot possibly see how we can let this resolution pass."
He gave no hint at the time that Russia had a rival resolution.
France's Ayrault, meanwhile, had flown from Moscow to Washington where he told reporters that Saturday's vote on the French draft would be "a moment of truth" for the Security Council, especially for Russia.
Council members need to decide: "Do you, yes or no, want a cease-fire in Aleppo?" he said after talks Friday with Kerry.
Both the French and Russian resolutions urge immediate implementation of the U.S.-Russia cessation of hostilities agreement and "immediate, safe and unhindered humanitarian access throughout Syria."
But France and its Western allies insist that the first step must be a bombing halt.
Britain's Rycroft echoed U.N. envoy de Mistura's view that the bombing of rebel-held eastern Aleppo, with a population of 275,000 civilians including 100,000 children and about 1,000 "terrorists," was indiscriminate.
"This is not about stamping out terrorism, this is about killing civilians," Rycroft told reporters. "We are all in favor of fighting terrorism in Syria but the biggest single killer of innocent civilians in Syria is the Syrian regime. The second biggest killer of innocent civilians in Syria is Russia, and it's only the third biggest killer of innocent civilians in Syria that is al-Qaida, Al Nusra and all the other terrorists."
There are other key differences in the two resolutions as well.
The French draft expresses the council's intention to take "further measures" — U.N. code for sanctions — in the event that any party to the Syria conflict doesn't comply with its demands. There is no mention of this in the Russian text.
The Russian draft also has two elements not in the French text.
It stresses "the urgent need to achieve and verify separating moderate forces from 'Jabhat Al-Nusra' as a key priority."
It also welcomes de Mistura's proposal for al-Qaida-linked militants formerly known as the Nusra Front to leave Aleppo in exchange for a halt to Russian and Syrian government bombardment and asks Secretary-General Ban Ki-moon to present a plan to the council to implement it.