WASHINGTON (Reuters) - Pro-Syrian government forces including Russian mercenaries amassed near U.S. and U.S.-backed forces last week in Syria, but a potential confrontation was defused after the U.S. military contacted Russian officers, U.S. officials said on Tuesday.
The latest incident in the Syrian province of Deir al-Zor, east of the Euphrates River, came a month after a similar buildup led to U.S. strikes that killed or injured hundreds of Russian contractors.
Defense Secretary Jim Mattis disclosed the buildup of forces in the last week while speaking to Pentagon reporters.
However, Mattis said that after U.S. forces spoke with their Russian counterparts, the pro-Syrian government troops pulled back.
“This was a recent development, but we think that the potential for a clash there, thanks to the Russian direction to this group, has been reduced,” Mattis said.
Mattis said he believed the forces were under Russian control.
The U.S. military also attempted to use a hot line with Russia to defuse a crisis in February when forces who later turned out to be working for a Kremlin-linked contractor were building up near U.S. and U.S.-backed forces in Syria.
When the opposing forces attacked, the United States unleashed hours of strikes and killed about 300 men in a major incident that both Russia and the United States sought to publicly downplay.
The incidents underscored the potential for further conflict in Syria’s oil-rich east, where the U.S.-backed Syrian Democratic Forces (SDF) alliance of Kurdish and Arab militias holds swathes of land seized in its offensive against Islamic State militants.
The U.S.-led coalition was set up in 2014 to battle Islamic State fighters in both Syria and Iraq, who were largely defeated last year.
Some 2,000 U.S. troops remain on the ground in Syria, allied with the Kurdish-led SDF alliance.
Mattis said he has not seen Turkish forces move against Manbij, which is located in northeast Syria about 30 miles south of the Turkish border.
Turkey has said it will drive the Kurdish YPG militia away from the Syrian border if it does not reach an agreement with the United States on a plan to remove the group from the Manbij region.
“There has been no move against Manbij and we continue our dialogue with the Turkish authorities about how do we sort this out,” Mattis said.
In January, Turkey’s army and its Syrian rebel allies began a military offensive against the YPG militia in Syria’s Afrin district and gained full control of the region over the weekend.
Reporting by Idrees Ali and Phil Stewart; Editing by Jeffrey Benkoe