On Friday Greek media reported that two Turkish F-16s entered Athens' flight information region without permission and were intercepted by Greek jets. Some 48 hours earlier, Turkish President Recep Tayyip Erdogan noted in a statement that there would be no such incursions. This latest move will likely complicate efforts for the Biden administration to assure Congress that Turkey can be trusted with 40 new F-16 fighter jets.

Erdogan has prioritized securing the F-16s prior to green lighting Sweden’s NATO bid, but experts warn Sweden's accession to NATO is not a done deal.

"It is likely that President Erdogan is looking to get assurances from the U.S. (namely Congress) that the sale of F-16 fighter jets will be approved before he ratifies Sweden’s membership. He is under no significant pressure to get this done earlier," Sinan Ciddi, non-resident senior fellow and Turkey expert at the Foundation for Defense of Democracies, told Fox News Digital.

Ciddi further noted in an essay in the publication 1945 that Erdogan could call a special session of parliament in a matter of days rather than wait for October to ratify Stockholm's membership to NATO. 

Biden, Erdogan talking

President Biden and Turkey's President Recep Tayyip Erdogan meet at the NATO summit in Vilnius on July 11, 2023. (Andrew Caballero-Reynolds/AFP via Getty Images)

When the State Department notified Congress of a potential F-16 sale to Turkey, it cited "NATO alliance unity" as a reason for the deal. Coming out of Vilnius, the administration has joined Congress in making deconfliction between Turkey and Greece as important to the alliance as the membership of Sweden and Finland.

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In recent calls with the Turkish president and Greek Prime Minister Kyriakos Mitsotakis, both President Biden and national security adviser Jake Sullivan said Washington sees de-escalation and calm in the eastern Mediterranean and stability in the Aegean Sea between Greece and Turkey as core U.S. interests.

Senate Foreign Relations Committee Chairman Robert Menendez and Gregory Meeks, the ranking Democrat on the House Foreign Affairs Committee, have insisted that congressional approval for Turkish F-16s would be contingent on ensuring American weapons could not be used by Turkey to challenge Greek sovereignty or territorial integrity.

World leaders shaking hands

Turkey's President Recep Tayyip Erdogan shakes hands with Sweden's Prime Minister Ulf Kristersson as NATO Secretary-General Jens Stoltenberg looks on at the NATO summit in Vilnius, Lithuania, Monday, July 10, 2023. (Yves Herman, Pool Photo via AP)

Before the intrusion into Greek airspace on Friday, Erdogan seemed to be on board. In a press conference in Vilnius, Erdogan declared, "We have never used our F-16s against Greece and we don’t plan to use them against Greece moving forward." In a move to perhaps further assuage Greek concerns, Biden recently talked about a defense package for Greece, including F-35 fighter jets which Congress has already signed off on.

Erdogan and Mitsotakis also met on the sidelines of the NATO summit in Vilnius and agreed to continue multiple levels of communications and to hold a meeting of the High-Level Cooperation Council in Thessaloniki in the fall.

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Two F 16 fighter jets

F 16 fighter jets take part in the NATO Air Shielding exercise near the air base in Lask, central Poland, on Oct. 12, 2022. (Radoslaw Jozwiak/AFP via Getty Images)

Erdogan said Turkey will move ahead with Sweden’s ratification process when the Turkish parliament meets in October. The United States and NATO allies want the deal to move faster, within the next two to three weeks. 

Although the sale is seen as a positive development for Turkey’s relationship with NATO and its newest member Finland (and potentially Sweden), the deal is still looked at with some consternation by U.S. lawmakers, who fear it was made at the expense of Greece.

Greece's Prime Minister Kyriakos Mitsotaki

Greece's Prime Minister Kyriakos Mitsotakis shakes hands with Turkey's President Recep Tayyip Erdogan at the NATO summit, in Lithuania, Wednesday, July 12, 2023. (Dimitris Papamitsos/Greek Prime Minister's Office via AP)

A group of lawmakers sent a letter to Secretary of State Antony Blinken on July 8 urging the Biden administration to include assurances in the F-16 package that Turkey is not allowed to use American weapons within the NATO alliance.

"Given Turkey’s history of using American F-16s for overflights in the Aegean and to challenge Greek sovereignty, we request mechanisms that provide for the pause, delay or snapback of the transfer of American weapons to Turkey if it resumes its destabilizing actions in the Eastern Mediterranean that threaten or undermine U.S. national security interests or NATO security architecture," the lawmakers wrote.

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The lawmakers are looking for oversight mechanisms, including snapback provisions, that could be used to put a hold on the F-16s in the event Turkey violates Greek territorial sovereignty. 

Despite concerns in Congress, some experts on the region don't think there's much to fear.

"Greece will now likely receive the F-35s following the sale of F-16s to Turkey. Therefore, the F-16 sale to Turkey will likely be met with a shrug in Athens, as it makes getting the much more advanced and more capable F-35s more likely. Given the trepidation in Congress over selling anything to Turkey, particularly from Sen. Robert Menendez, I assume this makes it likely that the U.S. will support a sale of the F-35s to Greece," Max Bergmann, director of the Europe, Russia, and Eurasia Program at the Center for Strategic and International Studies, told Fox News Digital.

Erdogan watches jets

President Recep Tayyip Erdogan observes a military exercise in Izmir, Turkey, on June 9, 2022. (Xinhua via Getty Images)

Many diplomats and observers believe that President Erdogan held Sweden’s NATO bid hostage, using their application to apply pressure on the United States to move forward with the sale of the fighter jets and military modernization kit. The United States has denied the allegation. 

NATO FINLAND

National flags fly outside NATO headquarters in Brussels, April 3, 2023. (AP Photo/Virginia Mayo)

"President Biden has been clear and unequivocal for months that he supported the transfer of F-16s to Turkey, that this is in our national interest, it's in the interest of NATO that Turkey get that capability. He has placed no caveats or conditions on that in his public and private comments over the past few months, and he intends to move forward with that transfer in consultation with Congress," Sullivan told reporters aboard Air Force One en route to the NATO summit in Vilnius, Lithuania.

Erdogan also rejected the notion that Ankara’s likely ratification of Sweden’s NATO membership was linked to the F-16 sales. The Swedish government took the necessary steps to alleviate Turkish concerns and promised to reignite Turkey’s path toward joining the European Union.

The Turkish president has made not so subtle overtures toward the West since winning re-election to a third term in May, extending his rule into its third decade.

"Turkey was given an opportunity to get back into the good graces of the NATO alliance and blew it by extorting its allies," said Endy Zemenides, executive director of the Hellenic American Leadership Council. "Turkey’s lack of reliability as an ally brought the tensions it causes within the NATO alliance front and center, and made maintaining stability in the Aegean – both via holding Turkey accountable and arming Greece – a declared U.S. interest."

Vladimir Putin and his Turkish counterpart, Recip Tayyip Erdogan meet at the Kremlin in 2020in Moscow

Russian President Vladimir Putin and Turkish President Recep Tayyip Erdogan shake hands during their talks at the Kremlin on March 5, 2020 in Moscow. (Mikhail Svetlov/Getty Images)

Other experts warn that Erdogan's maneuvers have more to do with a pragmatic and transactional approach to foreign policy than Turkey actually tilting toward the West, and any decoupling from Russia is unlikely in the near term.

"Recep Tayyip Erdogan and Vladimir Putin know each other perfectly, they aggravate each other on many topics, but always have a superior interest in cooperating. Let’s not forget that Russia has major stakes on all issues happening across Turkish borders, be it in Syria, in the South Caucasus, in the Eastern Mediterranean or in the Black Sea," Mathieu Droin, visitng fellow in the Europe, Russia, and Eurasia Program at the Center for Strategic and International Studies, told Fox News Digital.

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If Turkey doesn’t fulfill its end of the bargain, it would not be the first time the U.S. has placed an embargo on their NATO ally. Congress blocked arms sales to Turkey between 1975 and 1978 over the Cyprus conflict. Other arms sales have been put on hold since, notably the Trump administration removed Turkey from the F-35 fighter jet program after Turkey purchased S-400 surface-to-air defense system form Russia.