He added that four F-35s had already been delivered to Turkey and that the training of Turkish pilots at a U.S. base is ongoing. 

The two F-35s were already delivered to Turkey in June and are currently at Luke Air Force Base in Arizona where Turkish pilots are being trained. The jets were scheduled to be transferred in November this year.

Earlier April, the Pentagon said it transferred one of Turkey's two additional F-35 jets to Luke Air Force Base in Arizona.

However, the tensions between the U.S. and Turkey have reached a fever pitch in recent months with Ankara set to begin receiving the advanced S-400 Russian surface-to-air missile system that Washington said will jeopardize Turkey's role in the F-35 fighter jet program and which could trigger congressional sanctions.

Additionally, earlier this month, U.S. Vice President Mike Pence said Turkey's purchase of the S-400 system could potentially pose a risk to NATO.

Cavusoglu stressed that Turkey took the concerns of the NATO alliance into account in relation to Ankara’s planned purchase of Russian S-400 missile defense systems. 

"We need to take into consideration NATO's concerns [regarding S-400]. It is not true to say Turkey disregards them. We are always sensitive," he said.

"Our allies and NATO must also understand this very well. We need our air defense system urgently," added Cavusoglu.

He underlined that Turkey disagrees with claims that if it purchases the Russian systems, Moscow would be able to access F-35 systems and technology. 

Unity and solidarity

Cavusoglu's remarks came after a trilateral meeting to assess the outcome of a NATO foreign ministers’ meeting Washington earlier this month to discuss defense and security cooperation.

Highlighting the threat posed by Russia to the security of Europe, particularly with its activity in the region of Black Sea, Czaputowicz, said his country supported "stepping up" the military posture of NATO in the region.

"We [Turkey, Romania and Poland] also agreed that we have to demonstrate together at the NATO summit in London our unity and solidarity," Czaputowicz said.

Discussing military cooperation between Turkey, Poland and Romania, he added: "We already agreed [to hold] some meetings of leading companies from our three countries."

Meanwhile, Melescanu said one of Romania’s top priorities during its term presidency of the EU Council is to "accelerate and improve" the relationship between Turkey and Brussels.

"When we speak about Turkey, we speak about a candidate country and key partner of the European Union in its entirety," he added. 

Touching upon the security of the Atlantic, he said the western Balkans and southeastern Europe -- particularly Turkey -- was a region of strategic importance for Euro-Atlantic security.

"Our commitment to NATO's open-door policy contributes the fulfillment of this goal," Melescanu said.