WASHINGTON, Sept. 21 (Xinhua) -- U.S. and Russian military officials had met face-to-face somewhere in the Middle East this week on de-confliction measures in the fight against the Islamic State (IS) in Syria, the Pentagon said on Thursday.

"The discussions emphasized the need to share operational graphics and locations to ensure that prevention of accidental targeting or other possible frictions that would distract from the defeat of ISIS," said Ryan Dillon, a Baghdad-based spokesman for the U.S.-led coalition, at a Pentagon briefing, referring to another acronym of the extremist group.

Dillon declined to offer details on when or where the meeting occurred, but said that the exchange of information was focused on battles around Deir ez-Zor, where U.S.-backed rebel groups were operating close to Russian-backed Syrian government troops.

Dillon also indicated that follow-up meetings between U.S. military and Russian military would be held "perhaps in the same location."

To avoid air accidents over Syria during their airstrikes against the IS, the United States and Russia in 2015 were engaged in talks aimed at ensuring "deconfliction" of air operations in Syria.

According to Dillion, the de-confliction telephone lines include an air-to-air line, a line "talking ground stuff," and another line "that is between the commanders of the two sides."