Acting U.S. Defense Secretary Patrick Shanahan said on Tuesday that he expected to resolve a dispute with Turkey over its purchase of Russia's S-400 air defense system, a day after the United States halted the delivery of equipment related to the F-35 aircraft to Ankara.
The United States is at an inflection point in a years-long standoff with Turkey, a NATO ally, after failing to sway President Recep Tayyip Erdoğan that buying a Russian air defense system would compromise the security of F-35 aircraft.
But President Erdoğan has refused to back down from Ankara's planned purchase of Russian S-400 missile defense system, and said Turkey will take delivery of the S-400s in July.
On Monday, the Pentagon said it had suspended the delivery of equipment related to the stealthy F-35 fighter jet "pending an unequivocal Turkish decision to forgo delivery of the S-400."
If the Pentagon takes the next step and removes Turkey from the F-35 program, it would be the most serious crisis in the relationship between the two allies in decades.
Shanahan expressed optimism that both countries would find a way out of the crisis by persuading Turkey to purchase the Patriot defense system, instead of S-400s.
"I've had a number of conversations with Defense Minister (Hulusi) Akar and I really think we'll resolve this situation with our strategic partners," he said.
"I am very confident in the Patriot proposal that we've delivered to Turkey, its availability, it's pricing, and very importantly, the industrial participation that comes along with the Patriot system."
Shanahan added that he expected the United States to ultimately carry out the delivery of F-35s currently at Luke Air Force base to Turkey, after resolving the dispute. Turkish pilots are receiving training on two aircraft at Luke Air Force Base in Arizona.
Turkey has remained unfazed in the face of threats from the U.S., with many officials repeatedly stressing that the S-400 deal is not a threat to NATO systems and is not on the table to be used as a bargaining chip against F-35 jets and Patriot negotiations
Last week, Foreign Minister Mevlüt Çavuşoğlu met in Turkey with his Russian counterpart, Sergei Lavrov, and insisted that the S-400 purchase would go ahead.
The United States and other NATO allies that own F-35s fear the radar on the Russian S-400 missile system will learn how to spot and track the jet, making it less able to evade Russian weapons in the future.
In an attempt to persuade Turkey to drop its plans to buy the S-400, the United States offered the pricier American-made Patriot anti-missile system in a discounted deal that expired at the end of March. Turkey has shown interest in the Patriot system, but not at the expense of abandoning the S-400.
When Turkey wanted to the buy the Patriot missile system from the U.S. in 2009 during Barack Obama's term, U.S. Congress declined the offer for the sale of the Patriot PAC-3 batteries worth $7.8 billion at the time.
