If Turkey were removed from the F-35 jet supply chain amid a dispute with the United States over its planned purchase of a Russian missile system, it would impact the production rate for up to 75 of the fighters, a Pentagon official said on Thursday. The United States has halted delivery of equipment related to the stealthy fighter aircraft to Turkey. It was the first concrete American step to block delivery of the jet to the NATO ally in light of the planned purchase of Russia’s S-400 missile defense system.