In my previous column ahead of the meeting between President Recep Tayyip Erdoğan and U.S. President Donald Trump, I focused on the critical nature of personal chemistry between the two leaders.

Since the beginning of Trump's presidency, the two leaders have pretty regularly communicated with each other in face-to-face meetings or through phone calls. This has been an important factor in determining bilateral ties in the last two-and-a-half years.

Even in the tensest periods, the positive atmosphere at these meetings resulted in a change in the overall expectations for the future of bilateral relations. In fact, even the most pessimist pundits expressed surprise in the aftermath of these meetings. This has been true in the history of bilateral relations.

The positive chemistry between the leaders has proved to contribute to the resolution of disputes and divergences between the two countries and contain the crisis in relations. It was one of those moments when a positive atmosphere would be extremely vital to prevent a fallout in strategic relations.

During their meeting Saturday, the two leaders once again made a critical intervention in the state of bilateral ties. The press conference before the meeting reflected one more time the positive mood between the two leaders.

President Trump praised his ties with President Erdoğan and demonstrated that he understands the grievances of Turkey when it comes to constant threats of sanctions from different actors and some U.S. government institutions.

In his public remarks, he mentioned that Turkey was not treated fairly in regards to the debates surrounding the purchase of Russian air defense systems. He said "They wouldn't let him buy the missile he wanted to buy, which was the Patriots ... You have to treat people fairly. And I don't think he was treated fairly."

This refers to the previous Turkish attempts to purchase the air defense systems from the NATO allies. Since the beginning of the tension between the U.S. and Turkey, the Turkish government has mentioned its earlier efforts to buy these systems from the U.S.

The manufacturer in the U.S. failed to provide acceptable conditions, ignoring Turkey's expectations about the price, the delivery date and technology sharing. Beyond the absence of a favorable offer, due to the attitude of some members of the Congress towards Turkey, there was a high degree of skepticism in regards to its review process.

The instances where Congress did not want the sale of some U.S. manufactured weapon systems to Turkey have given way to this situation. After all these attempts, Turkey decided to purchase these systems from another manufacturer and it has since been trying to explain the process to the U.S. administration.

While many in the U.S. recognize this background of the S-400 debacle, the Turkish government and the public are witnessing, for the first time, the reaction of such high-level U.S. officials.

Following this meeting, there is a question mark in regards to the impact of this statement to the state of crisis between the two countries. For the last few months, there have been steps taken to exclude Turkey from the F-35 program and threats to implement sanctions on Turkey, both of which constitutes a significant breach of mutual trust and should be considered as a major threat to the strategic partnership between the two countries.

Now in the aftermath of President Trump's statements, the U.S. administration needs to take steps to resolve this crisis and to prevent actions that would hurt the spirit of an alliance and destabilize the relations in existing areas of cooperation.

At this point, President Trump's determination will be the key. As I said in my previous column "at this critical juncture it is up to Trump to put U.S. foreign policy with Turkey back on track. It will take more than stating the significance of the strategic partnership but rather acting on it."

This article was first published by Daily Sabah on July 1, 2019.