The United States has voiced “grave concern” over a military operation planned by Turkey in northeastern Syria.

“Unilateral military action into northeast Syria by any party, particularly as U.S. personnel may be present or in the vicinity, is of grave concern,” said Pentagon Spokesman Cmdr. Sean Robertson on Dec. 12. “We would find any such actions unacceptable.”

He said “coordination and consultation between the U.S. and Turkey is the only approach to address issues of security concern in this area.”

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