There is no concrete evidence to suggest how Turkey's Russian-made S-400s could harm F-35 jets or the NATO alliance, Turkish President Recep Tayyip Erdogan has said.
Speaking to Turkish diplomats in Ankara on Tuesday, Erdogan said he believed that US President Donald Trump would not allow Turkish-US relations to "become captive" to the S-400 issue.
"There is no evidence that the S-400s will somehow cause harm to NATO or the F-35. Earlier, many countries had purchased these systems, and its incorrect to ask Turkey about its relationship with the West. Turkey's purchase of the S-400s is exclusively a commercial move," Erdogan said.
The president added that he had previously proposed that Washington create a commission to discuss whatever concerns the US side might have about the S-400s.
A day earlier, Turkish Foreign Minister Mevlut Cavusoglu told reporters that Washington's attempt to link the S-400 purchase with Turkey's participation in the F-35 fighter programme was "completely" out of line with the spirit of the Turkish-US alliance, and expressed hope that the two countries could resolve their problems in the context of "existing friendly relations".
Turkey has invested over $1.25 billion into the plane's production, and had been engaged in the production of several components for the aircraft, making plans to buy up to 120 of the advanced jet fighters.
However, last month, following the start of deliveries of S-400 components to Turkey, the US announced that it would scrap its commitment to sell Turkey F-35 jets, with the White House considering sanctions against Ankara under the 2017 Countering America's Adversaries Through Sanctions Act.
Turkish officials have decried the F-35 decision illegal, and warned that it would harm the strategic relationship between the two NATO allies.
Late last month, Erdogan warned that Ankara might reconsider moving forward with a major order of Boeing aircraft if Washington followed through with its sanctions threats.
Earlier, President Trump said he did not blame Turkey for buying the Russian-made S-400s, saying there were "a lot of circumstances" which prompted Ankara to move forward wit the deal. During a recent face-to-face meeting with Erdogan, Trump blamed President Barack Obama for the S-400 situation, saying Turkey would have preferred to buy the US's Patriot missile systems, but was not offered the deal until it was too late.
The first batch of S-400s were delivered in July. Russia and Turkey signed a $2.5 billion deal for the missile systems in December 2017. A year later, the US cleared a $3.5 billion Patriot missile deal for Turkey, but Ankara has yet to accept, saying the terms proposed by the US aren't as good as its deal with Russia, which may include the possibility of producing some S-400 parts in Turkey at some point in the future.
US and NATO officials have repeatedly warned that the S-400s' presense in Turkey might allow Russia to collect sensitive information about NATO systems, as well as the F-35 fighter and its stealth capabilities. In May, a senior Pentagon official said the deployment of S-400s in Turkey would be "devastating," both for the F-35 programme and in terms of continued Turkish interoperability with NATO.