After four days of silence from the U.S. government since Turkey first took delivery of the Russian-made S-400 weapon system, President Trump and his nominee for Secretary of Defense each stated separately July 16 that Ankara will not receive the F-35 Joint Strike Fighter as a result of the deliveries.

“We are now telling Turkey … we’re not going to sell you the F-35 fighter jets,” Trump said in a televised press conference at the White House Tuesday.

An F-35 Lightning II streaks across the sky while doing maneuvers to the Eglin Air Force Base runway. The 33rd Fighter Wing-owned aircraft is a fifth-generation fighter and used to train pilots and maintainers. (U.S. Air Force photo/Samuel King Jr.)

The Pentagon has said for months that Turkey, a NATO member state and F-35 partner nation, cannot receive the fighter aircraft so long as it continues with the procurement of the Russian anti-aircraft system, of which it took delivery July 12. Lawmakers have also expressed strong opposition to the sale and the U.S. government has sought to persuade Turkey to procure the Raytheon [RTN]-built Patriot missile defense system instead.

Trump accused President Obama’s administration of blocking Patriot sales and forcing Turkey to look at the S-400. “Turkey had already signed and paid a lot of money to Russia for the missile system that they were not allowed to buy here, foolishly,” he added.

Army Secretary Mark Esper, who Trump has nominated to become the next secretary of defense, told members of the Senate Armed Services Committee (SASC) Tuesday morning that he has been “disheartened” to see how Turkey has “drifted” over the past few years as a longtime NATO ally.

He re-confirmed the Pentagon’s previous statements that the F-35 and S-400 are incompatible.

“The policy that I have communicated to my counterpart, if confirmed, … is you can either have the S-400 or you can have the F-35. You cannot have both,” he said in response to a line of questioning from SASC member Sen. Tim Kaine (D-Va.) “Acquisition of the S-400 fundamentally undermines the capability of the F-35 and our ability to retain that overmatch in the skies going forward.”

The steps that the Defense Department and other U.S. government agencies will take now that Turkey has taken delivery of the S-400 remain to be seen. The nation has a program of record for 100 F-35A jets, two of which are currently located at Luke Air Force Base, Arizona, where Turkish pilots are training. The Pentagon did not provide a comment on Tuesday by Defense Daily’s deadline.

Trump called it “a very tough situation” for both countries but added, “With all of that being said, we’re working through it. We’ll see what happens, but it’s not really fair.” He added that Lockheed Martin [LMT], the manufacturer of the F-35, “isn’t exactly happy. It’s a lot of jobs.”