U.S.-backed rebels took control of the strategic city of Ash Shaddadi on Friday after days of battling ISIS forces, the London-based Syrian Observatory for Human Rights reported. Meanwhile, thunderous airstrikes shook the city amid the fighting.
Opposition forces battling for Ash Shaddadi had previously cut the road between Mosul, Iraq, and Raqqa, Syria, and had taken several villages that ISIS once controlled, the observatory said.
Fighting was also underway Friday near the towns of al-Tool and Al-Hasakah, according to the observatory.
Meanwhile, Russia called for a U.N. Security Council meeting on Syria on Friday afternoon, two U.N. diplomats told CNN. Closed consultations were scheduled for 3 p.m., they said.
It's unclear whether the warring sides would go ahead with a "cessation of hostilities" and lay down their arms, but the days leading up to the scheduled truce has brought some good news. Aid convoys reached five besieged Syrian towns and delivered food to more than 80,000 people, according to the U.N. World Food Programme.
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"This marks a major humanitarian breakthrough in Syria, but we must remember that one-off and sporadic convoys can only provide temporary relief to hungry, desperate people," said Jakob Kern, the aim program's director for Syria. "People need to eat every single day."
The group said its team in the Damascus suburb of Moadamiya -- which the United Nations says it hasn't been able to resupply in two years -- found people living off grass and rice. It said rice sells for more than 50 times its price in Damascus.
'Put up or shut up'
The planned ceasefire was negotiated February 12 in Munich, Germany, among diplomats from more than a dozen countries, including the United States and Russia.
"This is a test," said Staffan de Mistura, the U.N. secretary-general's special envoy for Syria. "It is a test on what was decided in Munich. In Munich, it was clearly a commitment by everyone to ensure this would be happening."
The situation in northern Syria is growing ever more complex. The Turks and the Syrian Kurds, for example, are both fighting ISIS, both fighting the Syrian regime of Bashar al-Assad -- and also fighting each other.
Military officials from Russia and the United States held an unannounced meeting Thursday night in Geneva, Switzerland, ahead of wider Syria talks expected Friday, a U.S. State Department spokesman told CNN.
"It is good that for the first time there is direct coordination, including on military issues, between the U.S. and Russia," German Foreign Minister Frank-Walter Steinmeier said in a statement. "I hope that this will enable us at least to agree as a first step on measures to protect the civilian population."
But skepticism remains.
Assad, the Syrian President, said "no one" was capable of making the fighting stop.
Other critics doubt the proposed truce will work as the Syrian army, backed by Russian air power, pursues a major offensive in northern Syria.
If the Syrian regime does not agree to the truce, the civil war could continue to drag on, said Vitaly Churkin, Russia's ambassador to the United Nations.
The United States has accused Russia and Syria of carrying out airstrikes that hit hospitals and schools in northern Syria this week.
"They were Russian aircraft that carried it out, these strikes," said Mark Toner, a deputy spokesman for the U.S. State Department. "We're pretty confident in our assessment that this was Russia that carried out these strikes."
Moscow needs to "put up or shut up" when it comes to implementing the truce, he said.
The Russian Ministry of Defense denied any responsibility for the attacks in a series of tweets Tuesday.
The country has been accused of hitting moderate rebel groups with its airstrikes. Moscow denied it and maintains that it is targeting terrorists.
CNN's Nic Robertson, Ryan Browne, Elise Labott, Dana Ford, Radina Gigova, Frederik Pleitgen, Ben Brumfield, Jason Hanna and Richard Roth contributed to this report.
