Townsend, commander of the joint effort known as Operation Inherent Resolve, said USA troops were about three miles away from the strikes and that Russian Federation immediately stopped upon receiving notice.
Russian and Syrian aircraft bombed positions held by the US -backed Syrian Arab Coalition near the Syrian town of al Bab, inflicting casualties, the top USA commander in Iraq said on Wednesday, but Moscow denied that had happened.
Regardless of whether the Russians are lying about bombing the USA -backed forces (which they most likely are) or not, it is logical to believe that it was, as Townsend believes, a mistake.
The SAC forms part of a broader alliance called the Syrian Democratic Forces (SDF) comprising Kurdish and other groups that the United States has been training and advising to lead the anti-IS fight.
"I don't foresee us bringing in large numbers of coalition troops, mainly because what we're doing is, in fact, working", Townsend said.
Townsend said the Syrian Arab Coalition fighters suffered casualties but declined to say how many or whether there were fatalities.
It's unclear whether President Donald Trump will seek military coordination with Russia in Syria; his predecessor deemed it inappropriate, arguing that the Russians were at cross purposes with the U.S.by acting to prop up the Syrian government.
Townsend said the attack occurred southeast of al-Bab and 10-12 miles from Manbij city, in an area that ISIS fighters had been operating before withdrawing as rebel forces advanced. He said the USA leaves it to partnered forces to report on casualties they may suffer.
Suspend visa-free European Union travel for USA citizens, lawmakers say
Parliament argues that as a result the Commission has been "legally obliged" to take measures. The U.S. was warned along with Canada, Australia, Brunei and Japan.
The incident on Tuesday marked the second time in a month that Russian aircraft mistakenly attacked friendly forces.
Last August, Turkey launched a military operation in northern Syria to push ISIS off its southern border and keep Kurdish forces from advancing beyond the Euphrates river.
"There were US forces in the area", he added.
"And so we worked out an arrangement, a deconfliction".
Townsend said the U.S.is still talking to Turkey about whether and how Turkish forces might be involved in an assault on Raqqa. In early February, a Russian airstrike killed three Turkish soldiers in Northern Syria.
An analysis from the Institute for the Study of War Wednesday said if the Turks moved on Manbij, it would "derail the US -backed campaign against ISIS and create opportunities for al Qaeda to expand further in Syria".
It is unclear whether Townsend is disputing this plan, or simply doesn't consider thousands of troops in Syria to be a "large number" in the grand scheme of things.