Washington is reportedly increasing pressure on Ankara to speed up Turkey’s ratification of Sweden’s desired NATO membership, with reports out of the US capital pointing to a “warning” that otherwise the United States will promptly agree to sell F-35 fighter planes to Greece.

According to a report on Tuesday by the Washington D.C.-based correspondent of Greek state broadcaster (ERT), after the latest Turkish “foot-dragging” with Sweden’s application to join the Alliance, the Biden administration is considering a “formula” to sell the fifth-generation warplane to Greece and detach the prospect from another dealing with upgrades and sale of F-16s.

Other reports, albeit unconfirmed, have US Secretary of State Antony Blinken adding a stopover in Turkey in his coming overseas itinerary. If confirmed, a visit to Turkey by the top American diplomat ultimately aims to persuade Turkish leader Recep Tayyip Erdogan to push through the ratification process by the country’s national assembly when the latter opens in mid-January.

In case delays continue, sources claim, the Biden administration will officially inform the US Congress of its intent to sell the stealthy fighter planes to Greece, regardless of whatever displeasure is expressed by Ankara.

Blinken has previously said as much to his Turkish counterpart Hakan Fidan, in case pledges by the Erdogan government over Sweden’s membership aren’t fulfilled.