A United States delegation is expected to visit Turkey in order to discuss the Patriot missile sale with the Defense Industry Presidency (SSB) next week.

The visit is expected to be the first of the negotiation talks over the purchase of the Patriot missile defense system.

Last week, the U.S. made an official offer to Turkey for a $3.5 billion sale of the Patriot air and missile defense systems through another delegation's visit.

The system includes 80 Patriot missiles and 60 other missiles along with radar sets, engagement control stations and launching stations.

The offer came after the U.S. State Department on Dec. 19 approved a possible sale of the Patriot air and missile defense system and notified Congress of the proposal, saying that Turkey continues to be an essential element of the national security and defense strategy. The State Department also informed Congress about the sale proposal. The move was regarded as a breakthrough after Washington's delayed delivery of the F-35 aircraft to Turkey due to Ankara's purchase of the Russian-made S-400 missile defense systems.

Ankara is, on the other hand, opposing any prerequisite in the contract that foresees the cancellation of the S-400 defense systems. President Recep Tayyip Erdoğan also previously said the S-400 missile system negotiations between Ankara and Moscow are a done deal, and the U.S. was not in a position to say something about it, adding that Turkey needs both the Russian S-400 air defense systems and the U.S. F-35 fighter jets.

Turkey had been trying to purchase the air defense system from the U.S. for some time but was never able to get a commitment from Washington when it was needed most. As the U.S. failed to meet the defense needs of Turkey and risked losing its NATO ally, Turkey turned to Russia and decided to purchase Russia's S-400 missile system in 2017, which caused a major political impasse between the two countries.