India, Aug. 19 -- The United States is moving urgently to construct a formal deconfliction mechanism linking Israel, Turkey and Syria after Israeli fighter jets bombed a disused airbase in northwestern Syria, an operation that a senior American diplomat described on Tuesday as an "unnecessary escalation" threatening a fragile regional balance.

Tom Barrack, the US special envoy for Syria who also serves as Washington's ambassador to Turkey, told Reuters in a telephone interview that the absence of any warning to Ankara before the strikes on the Abu al-Duhur base had left Turkish forces watching Israeli aircraft approach their border with no advance notice, a gap he said could easily have triggered a Turkish military response.

"Thankfully...