As Türkiye has cleared the long-delayed path for Sweden's bid to join NATO, eyes have now turned toward the U.S.' prolonged approval of sales of F-16 fighter jets, which has been linked to Ankara's approval of Stockholm's application to join the military bloc.
The Turkish Parliament ratified Sweden's NATO membership bid on Tuesday, clearing the biggest remaining hurdle to expand the Western alliance after 20 months of delay.
All existing NATO countries must approve before a new member can join the alliance, and Hungary is now the only member that hasn't given Sweden the green light.
When Sweden and Finland asked to join in 2022 after Russia's full-scale invasion of Ukraine, Türkiye raised objections over the two countries' protection of terrorist groups. It endorsed Finland's membership in April last year but, along with Hungary, had kept Sweden waiting.
Türkiye had also been concerned by a series of demonstrations by supporters of the PKK terrorist group in Sweden, as well as Quran-burnings that roiled Muslim countries.
Sweden had since, among other things, amended its anti-terrorism laws, curbed the PKK's financial activities, convicted a suspect for money laundering and financing terrorism, extradited another suspect and lifted restrictions on arms sales to Türkiye.
Last month, Parliament's Foreign Affairs Committee consented to Sweden's bid in the first stage of the legislative process after President Recep Tayyip Erdoğan sent its accession protocol to lawmakers for approval.
Erdoğan has linked the ratification of Sweden's NATO membership to the U.S. Congress's approval of a Turkish request to purchase 40 new F-16 fighter jets and kits to modernize Türkiye's fleet. He has also urged Canada and other NATO allies to lift arms embargoes on Türkiye.
U.S. President Joe Biden's administration has repeatedly backed the deal and promised to move forward with the $20-billion sale.
It never formally tied the sale of the F-16s to Türkiye's ratification of Sweden's NATO application. However, some key members of Congress had said they would not support the sale unless and until Türkiye signs off on Sweden's accession to the alliance.
Administration officials and analysts expect relatively quick action on the F-16 sale after Türkiye ratifies Sweden's NATO membership. However, there is no clear time frame for the U.S. Congress to approve the deal.
On Tuesday, the U.S. State Department repeated the administration's backing for the sale.
"President Biden has long been clear that he supports modernizing Türkiye's F-16 fleet, which is an investment in NATO interoperability," a State Department spokesperson told Anadolu Agency (AA).
"This proposed sale will support the national security interests of the U.S., Türkiye and all NATO allies."
The official said Congress has a key role in reviewing arms sales and indicated that some lawmakers "have publicly said that Türkiye's approval of Sweden's application to join NATO is a key consideration before they can support the sale of F-16s to Türkiye."
Türkiye's request aims to replace the Air Forces Command's aging F-16 fleet in the inventory, which is planned to be phased out starting in the 2030s.
Ankara sought to purchase Lockheed Martin's more advanced F-35 fighter jets, but the U.S. removed it from the multinational program to buy and help develop and build the warplane in 2019 after it acquired S-400 air missile defense systems from Russia.
Frustrated by the prolonged process of its request to acquire F-16s, Türkiye has begun discussions to buy Eurofighters, produced by a consortium involving Germany, Spain, Italy and the United Kingdom.
Türkiye announced in November it was in talks with Britain and Spain to buy 40 Eurofighter jets, though Germany has objected to the idea. Ankara has been urging Germany to align with the NATO spirit.