(Bloomberg) -- Turkish President Recep Tayyip Erdogan said he will meet Joe Biden in Glasgow during the global climate summit, where discussions will focus on how the U.S. can reimburse $1.4 billion Turkey paid to procure F-35 fighter jets. 

“The most important item will be our F-35 issue,” Erdogan said late Tuesday, according to state-run Anadolu Agency, adding that he’ll talk with Biden at the COP26 that starts Oct. 31. “We will need to discuss with them how they will repay us.”

The U.S. Defense Department has confirmed consultations with Turkey on its order for F-35s. Washington barred Ankara from purchasing and co-developing the jets after it bought Russian air-defense missiles that NATO allies fear could be used to collect intelligence on the plane’s stealth capabilities.

The U.S. denied making any financing offer over Turkey’s request to purchase F-16 warplanes, after Erdogan said that may be a way of returning the $1.4 billion.

“The information we have that there is a plan to reimburse Turkey with F-16s, is this true or not? We will find out this at the highest level,” Erdogan said. “It would be appropriate for me to speak with Biden. If that’s the case, then we will have reached an agreement accordingly.”

Erdogan Seeks Biden Meeting to Talk $6 Billion Arms Deal Request

Turkey said it sent a formal request to the U.S. on Sept. 30 to purchase 40 new F-16 Block 70 aircraft and nearly 80 kits from Lockheed Martin Corp. to modernize its existing F-16 fighters. The deal is potentially worth $6 billion but its approval will be difficult to win, given Congress’s opposition to Turkey’s purchase of the Russian S-400 system. Turkey has so far refused to jettison the missile defenses as demanded by Washington.

Some members of Congress sent a bipartisan letter to Biden and Secretary of State Antony Blinken urging them to refuse Turkey’s request for the F-16s.

“We cannot afford to compromise our national security by sending U.S.-manufactured aircraft to a treaty ally which continues to behave like an adversary,” the lawmakers wrote, according to a statement Oct. 25. 

They said a sale to Turkey could threaten the security of close U.S. allies Greece, Israel and Cyprus. “We urge you to act in our national interest and for the sake of stability in the Eastern Mediterranean by refusing to reinforce Turkey’s aging arsenal of fighter jets.”

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