At the end of last year, Saudi troops were also reportedly stationed near Syria's largest oilfield, Al-Omar in the oil-rich Deir Ezzor region, in what was thought to be Saudi protection for experts of Saudi oil giant Saudi Aramco. According to the report of the Arabic service of Turkish news agency Anadolu at the time, the arrival of the Saudi soldiers at Syria's biggest oilfield coincided with the arrival of around 30 trucks carrying drilling and digging machinery. 

Incidents and altercations between the superpowers backing different sides in the Syrian conflict continue. Just this week, U.S. soldiers were injured in a skirmish with Russian troops, two U.S. officials told The New York Times, noting that the injuries were the result of a collision between vehicles, not gunfire.  

After a surprise announcement of pulling the U.S. troops out of Syria in October last year, U.S. President Donald Trump said that the United States would protect Syrian oil fields from ISIS.