Gen. Frank McKenzie stated that operations against Islamic State militants are on the rise again.
This statement came after the U.S. cut back due to the increased tensions with Iran.
McKenzie said the Kurdish leader wanted assurances that the U.S. would continue to help his fighters.
The U.S. declared an end to the Islamic State’s physical caliphate last March.
But in recent months there have been growing concerns of regrouping, particularly in the west where U.S. forces are not present.
Operations against IS were interrupted in recent weeks upon the U.S. drone strike that killed a top Iranian general in Iraq.
Fearing reprisals by Iran, the U.S. paused or slowed operations to beef up security in Iraq and Syria.
Iran, after several days, launched ballistic missiles at two military bases in Iraq where U.S. troops are stationed.
Several dozen were diagnosed with traumatic brain injury, but no one was killed in the attacks.
According to officials, US operations against the Islamic State group in Syria were reduced by half over that time.
But as McKenzie took stock of the situation during his day-long sprint across eastern Syria he said that has now changed.
According to officials, there are now about 750 U.S. troops in eastern Syria.
These troops spread across more than 150 kilometers from Deir el-Zour to the border region east of al-Hassakeh.
The U.S.-Syrian Kurdish relationship was strained after Trump last month ordered American troops out of northern Syria.
That gave way for a Turkish invasion of Kurdish-held towns and villages along a stretch of the border.
Kurdish and American forces are now re-operating in the region.
They are facing, however, a more complicated situation.
On Saturday, McKenzie warned the troops that Iranian proxy forces in Syria continue to be a significant risk to them.
