Saturday marked another shift from Russia in Syria, when Russian Foreign Minister Sergei Lavrov said Moscow would give air support to "patriotic" Syrian rebels fighting Daesh (ISIS). Plenty of Free Syrian Army groups rejected Moscow outright, but not everyone was so quick to decide.

A group of rebels in southern Syria said on Monday they may be willing to begin talks with Russia, but not before its warplanes stopped targeting rebel positions further north.

It's been almost a month since the Russian air force began backing forces loyal to Syrian President Bashar al-Assad. But an operation that began under the guise of striking only Daesh targets has quickly become something else—much to the irritation of US officials, Russian warplanes began striking rebel groups' positions in western Syria almost immediately, many of whom had been vetted and armed by the CIA.

But the same has not be the cases in the south, where rebel groups have clashed with government forces along the Jordanian border for months, but haven’t seen Russia’s planes yet.

That could be why rebels there are less ready to turn down Moscow outright. Issam al- Rayyes, a spokesman for the FSA's Southern Front, told the BBC his group "didn't turn down the offer," but before anything moved forward, Russia's strikes against FSA groups further north would have to stop.

We just said if the Russians are serious in their offer they should stop immediately targeting our bases and targeting the civil areas," he said. "We don't need the help now, they should stop attacking our bases and then we can talk about future cooperation."