Turkey's military struck the Syrian-Iraqi border to prevent YPG terrorists using the route to reinforce northeast Syria, as Ankara prepared to attack following a surprise U.S. troop pullback, Turkish officials told Reuters on Tuesday.
Turkey says it is ready to advance into northeast Syria now that the United States has begun withdrawing troops from the Turkey-Syria frontier in an abrupt policy shift by U.S. President Donald Trump.
The U.S. move will leave YPG terrorists long allied to Washington vulnerable to attack by the Turkish Armed Forces (TSK).
Turkish President Tayyip Erdogan will visit the United States on Nov. 13 at Trump's invitation, a White House spokesman said. On Monday, Erdogan said U.S. troops had started to withdraw after a phone call he had with Trump, adding that talks between Turkish and U.S. officials on the matter would continue.
On Tuesday, a U.S. official said U.S. Defense Secretary Mark Esper and Chairman of the Joint Chiefs of Staff General Mark Milley took part in the phone call, but the official did not provide further details.
"Given the likely military issues raised on the call between (Trump) and President Erdogan, Secretary of Defense Esper and Chairman Milley participated on the call," said the official.
Earlier, the Pentagon said Esper and Milley had been consulted by Trump "over the last several days" about a possible Turkish strike in Syria.
"Turkey has chosen to act unilaterally. As a result we have moved the U.S. forces in northern Syria out of the path of potential Turkish incursion to ensure their safety," U.S. Defense Department spokesman Jonathan Hoffman said in a statement.
A Turkish security official said one of the main goals of the overnight strike was to cut off a transit route between Iraq and Syria often used by the terror group "before the operation in Syria".
It was unclear what damage was done or whether there were casualties. One official described them as an air strike, while the other said the site was made "unusable through various means".
Trump praised Turkey as a trade partner, in a softening of tone hours after threatening to "totally destroy" Turkey's economy if it acted "off limits" in Syria.
Amid deepening humanitarian concerns, United Nations Secretary-General Antonio Guterres urged all parties in northeast Syria to exercise maximum restraint and protect civilians.
Turkey sought to underscore its determination to act. "The TSK will never tolerate the establishment of a terror corridor on our borders. All preparations for the operation have been completed," the Turkish Defence Ministry said.
Near the Turkish border town of Akcakale, across from Syria's Tel Abyad, a Reuters witness saw howitzers placed behind earth embankments on Turkey's side of the border, pointed towards Syria.
Some 60 km (40 miles) to the west, multiple launch rocket systems mounted on two trucks were deployed behind earth embankments near Suruc, opposite the Syrian border town of Kobani. Artillery was also stationed in the area, and soldiers wandered around a nearby military camp.
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."