Turkish media outlets and social media are abuzz with a reported US offer to allow Turkey back into the highly advanced, fifth-generation F-35 stealth fighter program if Ankara place its Russian-made S-400 air defense systems at Incirlik Air Base, in southern Turkey, which is also home to US military personnel.

First reported on Sept. 22 by the Greek daily Kathimerini, the offer, if real appears to be the most serious one yet from the Biden administration on Turkey rejoining the F-35 program. Ankara, however, appears unmoved.

On the sidelines of the UN General Assembly gathering in New York this week, President Recep Tayyip Erdogan and Turkish officials criticized ongoing US defense sanctions against their country. In response to American journalists' questions about talks between Ankara and Washington, Erdogan said there were “no developments” regarding the F-35, according to the Turkish presidency’s communications directorate.

Turkish experts who spoke to Al-Monitor expressed skepticism over an F-35-for-S-400 deal from both a technical perspective and in terms of political feasibility. Especially salient for Turkish observers is skepticism of US intentions and the possibility that Turkey might in the end be stuck with no F-35s, no F-16s and no S-400s either.