Turkey’s military struck the Syrian-Iraqi border to prevent Kurdish forces using the route to reinforce northeast Syria, as Ankara prepares to launch an offensive there after a surprise US troop pullback, Turkish officials told Reuters on Tuesday. Turkey says it is ready to advance into northeast Syria, after the United States began pulling back troops from the Turkey-Syria frontier in an abrupt policy shift widely criticized in Washington as a betrayal of America’s allies. The US move will leave Kurdish-led forces long allied to Washington vulnerable to attack by the Turkish Armed Forces (TSK), which brands them terrorists because of their links to Kurdish fighters who have waged a long insurgency in Turkey. Giving details of the overnight strike, a security official said one of the main goals was to cut off transit route between Iraq and Syria often used by Kurdish armed groups “before the operation in Syria”. “In this way, the group’s transit to Syria and support lines, including ammunition, are shut off,” the official said. It was not clear what damage was done or whether there were casualties. Details of the strike, a joint operation by Turkey’s intelligence service and the military, were hazy. One official described them as an air strike, while the other said the site was made “unusable through various means”. US President Donald Trump publicly warned Turkey it would be in "big trouble" if any American personnel in Syria are injured during the military operation. On Monday, he tweeted: “As I have stated strongly before, and just to reiterate, if Turkey does anything that I, in my great and unmatched wisdom, consider to be off limits, I will totally destroy and obliterate the Economy of Turkey (I’ve done before!)” His remarks, reiterated on Tuesday in slightly modified form, met an angry response in Turkey, including from opposition party politicians such as Iyi Party leader Meral Aksener. “Threatening Turkey’s economy is a diplomatic catastrophe,” she told her party’s lawmakers in a speech in parliament. “The best response to this insolence is to go into the east of the Euphrates and break the terror corridor.” But on Tuesday, Trump tweeted: “So many people conveniently forget that Turkey is a big trading partner of the United States ... They have been good to deal with.” Trump said he will meet with Turkish President Recep Tayyip Erdogan at the White House on November 13. As for the Kurds, Trump said their “wonderful fighters” continued to receive US help with finance and weapons. The Kurdish-led forces have denounced the major US policy shift as “stab in the back”.