Foreign Minister Mevlüt Çavuşoğlu said yesterday that Turkey is ready to do what is necessary if the People's Protection Units (YPG) do not cross east of the Euphrates in Syria.Speaking at a press conference, Çavuşoğlu reminded the U.S. of its promise regarding the postoperative plan to pull back YPG forces in accordance with the agreement between the two parties. "The YPG has to cross east of the Euphrates. Otherwise, we will do what is necessary," Çavuşoğlu said.Çavuşoğlu underlined Turkey's determination in fighting against all terroist groups. Underscoring that there is no difference between the PKK, the YPG and DAESH, he said, "We will maintain our fight against these organization, as the last two attacks in Ankara both came from PYD camps in Syria." The foreign minister also raised important questions, asking, "Where does DAESH get their weapons from? Who gives the weapons to them? Where do these weapons come from?"Meanwhile, U.S. Vice President Joe Biden told YPG elements to return to east of Euphrates. Speaking at a joint press conference with Prime Minister Binali Yıldırım, Biden asserted that the YPG will not receive any more help from the U.S. if it does not keep its promises.Commenting further on operation Euphrates Shield, Çavuşoğlu stated that the operations of the Turkish Armed Forces (TSK) are being carried out as planned and the TSK is currently working together with a coalition to provide air support. "The aim of this operation is to eradicate the DAESH terror organization from the other side of our border. We are maintaining the [counterterrorism] fight with all the forces we have," Çavuşoğlu said, adding that the Free Syrian Army (FSA) has crossed the border and entered the area. The foreign minister said that Turkish Army tanks are working to guarantee that the Syrian Army crosses east of the Euphrates.Çavuşoğlu also referred to controversial tweets made by the head of the PKK's Syrian offshoot Democratic Union Party (PYD) Salih Muslim on Wednesday, referring to a tweet in Arabic and English that says: "Turkey is in a Syrian quagmire. [It will] be defeated as DAESH [was defeated]," along with the tweet "Turkey will lose a lot in the Syrian quagmire," tweeted in Turkish by Müslim.The foreign minister addressed these tweets, asking, "Why did Salih Muslim or the PYD feel uncomfortable? Didn't they claim to be fighting DAESH?" The minister went on to say that "If their purpose was to fight DAESH and to ensure integrity in Syria, they would have supported such an operation in fighting DAESH, rather than opposing it." Çavuşoğlu went on to say: "We would like to thank [the PYD] for confessing what we have long been trying to tell our allies: They have a secret agenda to form a canton, a Kurdish state, in the area."According to a statement from the office of the Prime Ministry, the Turkish army launched a cross-border operation Wednesday called "Euphrates Shield" along with a U.S.-led coalition in Syria's northern border-city of Jarablus to clear the area of DAESH.