It said "there are Russian citizens in Syria who went there with various goals" and "it is not up to the foreign ministry to evaluate the legality of their decisions". "But they took direction from someone", Mattis told reporters flying back to Washington with him from a trip to Europe, according to a Pentagon transcript.
The ministry denied the relation of the killed and the wounded with the regular Russian armed forces.
"Was it local direction?"
Russian officials refuse to admit Russian mercenaries are in Syria despite mounting reported evidence that they are active fighting in the interests of the Syrian government.
Mattis said he "understood" that Moscow had acknowledged contractors were involved, without elaborating on whether that understanding came from press reports.
The Russian Defense Ministry said in a statement earlier this month that a pro-Syrian government militia unit conducted a reconnaissance and search operation on February 7 in the vicinity of an oil refinery in the province of Deir al-Zour to identify and destroy a bandit group responsible for shelling government troop positions, and came under fire from the US -led coalition and its local allies.
The mercenaries were apparently working for a private Russia-based military company called the Wagner Group.
Russia's assistance has proved to be a major success as Syria has managed to liberate key areas over the past years, including the second largest city of Aleppo, relying on Russia's air cover and military advice. Participated in the fighting in the Donbas and in Syria on the side of Russian Federation.
The U.S. military has said the attacking forces were aligned with the Syrian government and were backed by artillery, tanks, multiple-launch rocket systems and mortars.
"So, whatever happened, we'll try to figure it out". We'll work with, obviously, anyone who can answer that question, but I cannot, at this time.