CNN video shows a group of American armored vehicles and trucks on the road near Rmeilan.
The Pentagon declined to give an official comment on troop movements, citing security reasons.
The move comes a day after US Defense Secretary Mark Esper, speaking at NATO headquarters in Brussels, said United States forces in Syria are "now taking some action" to strengthen their position in the Deir Ezzor region in eastern Syria to prevent ISIS from taking control of the oil facilities there and that will include some "mechanized forces."
The US was taking action to "ensure that we can deny ISIS access to the oil fields," Esper said. "Because we want to make sure they don't have access to resources that may allow them to strike within the region, to strike Europe, to strike the United States."