Turkey’s set to sign an agreement with Russia to jointly produce missiles and receive know-how to develop its own defense systems, a step that could boost criticism from its NATO partners that Ankara is moving away from the bloc.

“We will sign a deal after agreeing over final details regarding joint production or production of some parts in Turkey, and technology sharing,” said Ismail Demir, head of Turkey’s top defense procurement body, known as SSB.

The talks are part of Turkey’s deal to purchase a second S-400 missile-defense system from Russia and have reached a “quite ripe” stage, Demir said on Friday in Ankara. “The signing of a deal is just around the corner,” he said.

The comments show Turkey remains undeterred by the prospect of American sanctions over its push for the S-400 missiles. The two NATO allies have been sparring over the potential risks posed by the purchase to the Pentagon’s costliest weapons program, the F-35 fighter jet built by Lockheed Martin Corp.

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