There are several things that could trigger the U.S. to take economic action against Turkey.
Some of President Donald Trump's staunchest allies aren't on board with the White House's abrupt Sunday night announcement that US troops will begin withdrawing from Turkey's border in northeastern Syria.
Turkey has threatened for months to launch a military operation across its border with northeastern Syria, saying it wants to create a "safety zone" there.
The Turkish leader has repeatedly expressed frustration with Washington's support for Kurdish groups in Syria.
The move was denounced as a "stab in the back" by the Kurdish-led forces who have been Washington's most capable partner in fighting Islamic State in Syria.
On Saturday, Erdogan said a military incursion into northeastern Syria was imminent, after Ankara accused Washington of stalling efforts to establish a safe zone there together.
Turkey hosts more than 3.6 million Syrians who fled the civil war that began in 2011.
Jay Gruden out as Washington Redskins’ coach
On his way out, he delivered a quote that everyone's citing now that he's out: "If the key works Monday, I'll keep working". The NFL is similar to a grade school class when a team fires their head coach and makes one of the assistants an interim.
Turkey says the YPG is a "terrorist offshoot" of Ocalan's Kurdistan Workers' Party (PKK).
SDF spokesman Kino Gabriel said on October 7 that the group had been "stabbed in the back" by the "surprise" USA statement.
"To say he's an ally of America is nonsense", Robertson said.
"We advise those who have gone astray to return to the nation, because the nation is their final destiny", he added, encouraging Syria's Kurds to reconcile with the government.
Commenting on Trump's support for the Turkish plans, Thornberry said: "While we want to see the negotiated withdrawal of all foreign forces from Syria, it is an utter disgrace for the Trump administration to stitch up a deal with Turkey over Northern Syria, which leaves the Kurdish community at their mercy and risks opening up a risky new front in this war".
The UN said Monday it was "preparing for the worst" in northeast Syria.
Trump on Monday defended the decision, saying he was fulfilling a campaign promise to withdraw from "endless war" in the Middle East, and he warned Turkey that he would ruin its economy if any American personnel are harmed.
Turkish Foreign Minister Mevlut Cavusoglu said Monday that Turkey would "clean up terrorists" in Syria.