Ever since the American remarks about a "border army" in Syria, Turkey has been threatening to take action.
North Atlantic Treaty Organisation has also recognised Turkey's right to self-defence, but urged Ankara to do so in a "proportionate and measured way".
The battles had actually begun the night before but only with shells from Turkey against Kurdish forces under U.S. command.
The European Union's diplomatic chief Federica Mogherini said Monday she was "extremely worried" by Turkey's offensive against Kurdish militia targets in Syria, saying she would seek urgent talks with Turkish officials. More recently, Ankara also intensified its pressure on Washington to stop arming the Syrian Kurds.
Tillerson said: "We have five key goals in Syria".
Afrin has been a major hideout for the PYD/PKK since July 2012 when the Assad regime in Syria left the city to the terror group without putting up a fight.
During a meeting with Barzani, Ali Shamkhani, the secretary of Iran's Supreme National Security Council, addressed attacks made by Kurdish forces against Iranian border guards.
While the Trump administration has thus denied the report that caused the invasion and discouraged it, Secretary of Defense James Mattis told reporters Sunday that Turkey "has legitimate security concerns" for launching the invasion. Turkey was immediately upset by the decision, and the usa moved to placate Turkey by giving it a database with the serial numbers of weapons provided to YPG fighters so that they could track their use.
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She will remember this moment for all her life. "It's gonna be very exciting for me and hopefully I can be ready for that match". Kostyuk , who was all smiles when she met her opponent at the net, sobbed in her mother's arms shortly after.
While Washington wants to preserve its relationship with Turkey.it also has ties to Kurdish and other forces forces targeted by Turkey.
On Monday, the Afrin villages of Shankal, Qorne, Bali and Adah Manli were reportedly captured, along with rural areas including Kita, Kordo and Bibno, according to Turkey's state-run Anadolu news agency.
But Erdogan expressed impatience with USA demands to set a clear timetable, saying the campaign would be over "when the target is achieved".
While Washington and other Western capitals expressed concern, Turkish President Tayyip Erdogan said he had secured a go-ahead for the campaign from Russian Federation, principal backer of Syrian President Bashar al-Assad, long Turkey's foe. Iran expresses concern and Syria's Assad condemns the operation. For the Turkish government, any training of these fighters is seen as a threat and the leadership of Turkey has indicated that if the US continues its training efforts, those actions will negatively impact the relationship between the two countries.
The YPG's Afrin spokesman, Birusk Hasaka, said there were clashes between Kurdish and Turkey-backed forces on the third day of the operation.
Turkish forces and their Syrian rebel allies began their push to clear YPG fighters from the northwestern enclave on Saturday, opening a new front in Syria's civil war despite calls for restraint from United States, reported Reuters.