By Adham Kako, Levent Tok

ANKARA

The U.S. administration has threatened the Syrian opposition against supporting Turkey’s planned military operation in Syria, east of the Euphrates River, near Turkish borders.

As Turkish President Recep Tayyip Erdogan on Wednesday announced that an operation to clear the region, located east of the Euphrates, of the YPG/PKK terrorists will start "in a few days", the U.S. Administration started a campaign to obstruct the operation.

The American intelligence and diplomatic officials began threatening the Syrian opposition, with U.S. President Donald Trump and Cabinet secretaries and military officials conveying their "concerns" in phone calls to their Turkish counterparts in Ankara.

In a message to the Free Syrian Army and National Coalition for Syrian Revolutionary and Opposition Forces (SMDK), the U.S. officials called on them to not support the planned Turkish operation.

"Any participation by the Syrian National Coalition or the Free Syrian Army in any way is an attack on the United States and the Coalition Forces, and it will lead to direct confrontation with Coalition Forces and the United States of America. That will fully destroy the relations between the United States and the Syrian National Coalition and the Free Army," the message read.

The message further read: "US forces and Syrian Democratic Forces (SDF) [that is, YPG/PKK] are intertwined so that Syrian Democratic Forces (SDF) cannot be attacked without aggression and confrontation with Coalition Forces and US forces and advisers."

"When elephants dance, you must stay away from the dance floor," the U.S. officials said.

Previously, Turkey launched two successful anti-terror operations since 2016 to foil the formation of a “terror corridor” along Turkey’s border.

In its more than 30-year terror campaign against Turkey, the PKK -- listed as a terrorist organization by Turkey, the U.S. and the EU -- has been responsible for the deaths of some 40,000 people, including women and children. The YPG is its Syrian branch.