Head of the Presidency's Foreign Relations Department Ayşe Sözen Usluer said that Turkey's fight against terrorism on its southern border, including on the eastern bank of the Euphrates, will continue with determination while adding that the eastern bank of Euphrates will probably be secured by both the Turkish and Iraqi armies.

With respect to the U.S. Secretary of State Rex Tillerson's recent visit to Turkey, Dr. Usluer said that she is positive about the visit and said added that she believes the US will keep its promises and will force YPG to withdraw from Manbij.

Regarding comments about the future of Turkey's relations with NATO Dr. Usluer stressed that Turkey won't change its international position and will continue to be a member of NATO. In the meantime she also said that Turkey no longer feels the need to decide between the West and East while underlining that the country decides according to its interests, ideals or realpolitik; therefore, Turkey chooses what it thinks is in its best interests.

Touching upon the upcoming trilateral Syria summit that will take place in April at İstanbul with participation of Turkish President Recep Tayyip Erdogan, Russian President Vladimir Putin and Iranian President Hassan Rouhani ,Usluer said that this summit will definitely yield more positive results and she added that the results of this meeting are to be united with the results of the Geneva process.Daily Sabah: As Turkey's Operation Olive Branch continues successfully, some pro-regime militias attempted to enter Afrin to fight against Turkey last week but were repulsed. How do you evaluate the YPG and pro-regime militias uniting against Turkey, despite being enemies themselves?

Ayşe Sözen Usluer: It's been over a month since the initiation of the Operation Olive Branch (OOB). It's an operation that was launched according to the U.N. Charter Article 51, aiming to ensure Turkey's national security. In this respect, the ongoing operation is legitimate and this legitimacy is supported by numerous countries. The U.S. has had some mixed reactions; but is yet to interfere with the operation. Besides ensuring Turkey's national security, this operation also aims to facilitate political resolution in Syria and protect Syria's territorial integrity. The Democratic Union Party/People's Protection Units (PYD/YPG) are a separatist terrorist organization. Even though the Syrian Civil War seems like a conflict between the opposition and the regime, it was PYD/YPG who exploited this situation. They are the originators of the separatist movement in Syria. While the opposition is demanding democracy, PYD/YPG seeks the separation of territory. By removing the central government out of picture, they aim to achieve full autonomy in the short-term and to declare independence in the long-term with the support of the U.S.

In this respect, the regime backing PYD/YPG is completely irrational as these terrorists want to divide Syria ethnically and have already announced Afrin, Cizre and Kobane as cantons.

We're talking about an organization that has already drawn its borders, attempted to control oil and natural gas reserves in Deir ez-Zor, and started to organize its own administration in regions that were cleansed of Daesh. It's hard to understand why the regime is trying to protect this organization and objecting to Turkey's operation. Right from the start, Turkey has been expressing that the operation isn't an invasion. Turkey has asserted that it respects Syria's territorial integrity and will withdraw when security is established countless times. Therefore, with regards to Syria's territorial integrity, the regime shouldn't be afraid of Turkey.

Similarly, Iran and Iranian militia interfering with the operation in Afrin and supporting YPG over the Turkish army is inexplicable. Apparently, the task imposed to PYD/YPG by the US is more than cleansing Daesh. The larger implications are to diminish Iran's influence over Syria, cutting the ties between Iran, Hezbollah and the Syrian regime to ensure Israel's security. If we are to say more, we can say that the aim is to legitimize Israeli occupation in Golan Heights. For this reason, Iran and Iranian militia has to revise their stance against Turkey. The YPG isn't only the problem of Turkey, but the whole region.

DS: Certain circles in Turkey express that reestablishing communications and cooperating with Assad is a must to resolve the PYD/YPG issue and achieve stability in Syria. What is your take on this perspective?

ASU: From 2011, Assad has been killing his fellow citizens and even using chemical weapons on them. Assad has lost his political legitimacy. However, Russia entering Syria in 2014 and establishing both air and naval bases there, announcing they have rented these bases for 49 years, indicates that Russia aims to be a permanent actor there. Until Russia's intervention, we have been asserting that our Western allies should be engaged in this war. We even suggested very concrete propositions to them like establishing a safe zone and a no-fly zone to protect civilians. As they failed to heed our words, there was an influx of refugees in 2015 and 2016, first towards Turkey then to Europe. The most recent statements from the West indicate they want Assad out of the picture. It's not possible to understand this; while Turkey was advocating the same thing as early as 2012, they were all silent. They're talking about this now because Russia and Iran are in Syria and they have the intention to become permanent actors there. Since he serves Russia's interests, Assad is unwanted by the West now. This is a president who has killed around 1 million people according to some unofficial records and the West is saying he has to go only because he is serving Russia's interests. This kind of approach has no support from the popular base. Indeed, when the day comes, people of Syria will determine their future freely and Assad won't be there anymore.

Even if Turkey reestablishes relations with Assad, it would be to protect the rights and interests of the opposition. Yet, this doesn't mean Assad has any kind of legitimacy, as it's only earned through the support of the people.

DS: How do you evaluate the U.S. Secretary of State Rex Tillerson's visit to Turkey? Do you believe the joint mechanisms to be formed will be enough for resolving the mistrust between the two countries?

ASU: I believe all parties had good intentions at this meeting. It was an extensive and comprehensive meeting that lasted 3 hours 15 minutes. However, in terms of our relations with the U.S., we can't say that it is the heyday. Meanwhile, both Turkey and the US don't want to cast their strategic partnership and alliance aside. Syria is only a chapter of Turkey-U.S. relations; there are many other aspects like economic and cultural ties, touristic activities, student exchanges, Turkish diaspora living in the US as well as defense cooperation. Therefore, I don't believe any party wants to permanently damage relations.

Both sides of this disagreement are trying to resolve the issues. We have crises in two fields: FETÖ and the US support for YPG. During Tillerson's visit, it was decided to form joint technical commissions in the fields of justice, defense and foreign affairs. These commissions will discuss certain issues and attempt to defuse any crisis before reaching climax. So, we are hopeful and positive about the visit.

DS: Before Tillerson's visit, several generals at the Pentagon stated that Turkey shouldn't enter Manbij and that the US would continue to support the YPG. Do you believe a conflict between Turkish and American forces is possible, despite Tillerson's visit?

ASU: This is a situation both sides will want to avoid. Tillerson's statements after his visit suggest that the U.S. will work on the Manbij issue and will try to resolve it. I believe we can progress in terms of Manbij. Because, ultimately, I think the strategy determined by the Turkish Armed Forces (TSK) will be employed in the region that stretches up to Iraqi border.

DS: Could you elaborate on the last part? How could we progress in terms of the Manbij issue?

ASU: The US promised that YPG and PYD would withdraw from the city after cleansing Daesh. Manbij consists mostly of a Sunni Arab population. Therefore, YPG isn't fit to administer that region. If they attempt to alter the demographics of the region as they have done in so many regions, it would cause trouble in the long-term. I believe the US will keep its promise and will force YPG to withdraw from Manbij.

DS: How will Turkey's fight against terrorism continue on the eastern bank of the Euphrates?

ASU: The TSK's strategy will determine how the operation proceeds. Yet, the eastern bank of Euphrates will probably be secured by both the Turkish and Iraqi armies. I believe it is possible to achieve this by launching an operation against the PKK in Sinjar region. Nevertheless, how the operation proceeds will be determined by the TSK ultimately.

DS: So, a new front in Sinjar may be created by Turkey to eliminate terrorist elements?

ASU: As I have said, the TSK will determine this according to viability and necessity. However, as far as I see, military operations may aim to surround the enemy.

DS: Especially during the first days of the OOB, Turkish army planting flags in liberated regions were perceived as an invasion by certain critics. What would you like to say about it?

ASU: It's all about the context. Two sides are fighting; there is a victor and a defeated along with captured land. Therefore, the Turkish flag is planted to announce the victory and doesn't mean Turkey has any intentions to occupy that land. Moreover, it doesn't mean that it has become Turkey's territory. As I have said before, Turkey doesn't have and never had any expansionist policies; it's all about securing the border.

DS: There are comments about the future of Turkey's relations with NATO every time there is an issue with the US. In your opinion, does Turkey intend to leave NATO?

ASU: As you may remember, in last previous interview we talked about Turkey's new position in the international arena after the July 15 coup attempt. I said that Turkey wouldn't change its position.

Turkey no longer feels the need to decide between the West and East, or, as in a bipolar world, decide between the US and Russia. Turkey is aware that it is a prominent member of NATO and doesn't shy away from underscoring this fact. Turkey always expresses that it will continue to be a member of this organization. In short, these kinds of comments are made by those who are having a hard time understanding the shifting balances in the international community. They believe that Turkey has to choose between two existing blocs, as if the Cold War hasn't ended. However, Turkey positions itself at an equal distance two both sides. The country decides according to its interests, ideals or realpolitik; therefore, Turkey chooses what it considers the best choice.

This is the main reason why Turkey is closer with Russia and Iran. President Erdoğan and President Putin talk over phone 8 times a year and meet 5 times. So, it's natural. Meanwhile, we have 911 kilometers long border with Syria; Russia and Iran have become prominent actors there.

The Western alliance failed to even attempt an initiative in Syria, showing extreme unwillingness. So, Turkey is holding these meetings and is engaged there. Some commentators might even go further to discuss shift of axis but it's not even related to that phenomenon. All in all, Turkey's NATO membership is indisputable.

DS: What should be expected from the Istanbul Summit that is to be held in April with the participation of Turkish, Russian and Iranian presidents?

ASU: These three countries initiated the Astana process. Astana aims to form non-conflict zones in Syria and achieve ceasefire. We could say it's largely a success. The same three countries also initiated a new political process dubbed the Sochi process that will contribute to the Geneva process. As a part of the Sochi process, the Syrian People's Congress was held. The results of this congress were important. The establishment of a constitutional commission was decided; Turkey, Iran and Russia proposing names for this commission. This will definitely yield more positive results. More importantly, a declaration acknowledging that this meeting was complementary to the Geneva process was produced. The results of this meeting are to be united with the results of the Geneva process.

Even though Turkey is a part of this process together with Russia and Iran, it believes the Syrian crisis could only be resolved with a more extensive approach including more actors, especially those in the West. Turkey is sure that the ultimate resolution of the conflict will be achieved with those present in Geneva. At this upcoming summit, PYD/YPG not being a part of Syria's future and restructuring the Syrian state to address Syrian people's democratic demands will be discussed.

DS: Revision of the Customs Union Agreement is also crucial for Turkey. As Germany had reservations in this issue last year, the negotiations between Turkey and the EU weren't initiated. Do you believe Turkey and the EU will be able to initiate the negotiations for Customs Union in 2018?

ASU: I believe we will be able to initiate the negotiations. These issues are currently being discussed by the technical commissions. Moreover, the estimations suggest that the revision of the Customs Union will contribute more than US$6 billion to the EU, while contributing around US$14 billion to Turkey.

Both parties should take this into consideration. After Brexit, the UK started to seek to strike a Customs Union deal with the EU. Even though the revision of Customs Union is beneficial for all, our main focus is becoming a full member of the EU.