The Pentagon fought back against President Donald Trump’s surprise decision to remove US troops from northeast Syria to allow a Turkish operation, a senior administration official told Al-Monitor on Monday.

In internal US administration discussions before the White House announced Trump’s decision, Pentagon officials argued that Turkey had used negotiations for a northeast ‘safe zone’ to scout a military operation against the US-backed Syrian Democratic Forces, known as the SDF.

“Certainly not a surprise to most, the [Department of Defense] opposed the decision to allow the Turkish operation,” a senior administration official told Al-Monitor. The official added, “We have spent considerable time and effort to build the safe zone under the expressed idea that it would appease the Turks and prevent an incursion. The Turks just used it as a way to conduct reconnaissance for their operation. That was completely deceptive on their part.”

As US troop elements have begun to pull back from Syria’s contested border with Turkey, a separate defense official said Defense Secretary Mark Esper will be “reaching out to affected allies today,” though it was not clear whether the Pentagon would be contacting the SDF, who criticized the American pullback as a betrayal on Sunday.