The US ambassador to Turkey said on Friday that they hope the S-400 issue between Turkey and the US can be resolved, Anadolu Agency reports.
"We hope that the issue of S-400 can be resolved. But if it cannot be, we will continue to focus on all the areas of our cooperation that are not directly affected by the sanctions which we put into place," David Satterfield told reporters, evaluating Turkey-US relations.
On December 14, the US imposed sanctions on Turkey over the its acquisition of the Russian S-400 missile defence system.
US officials have voiced opposition to the deal, claiming the S-400s would be incompatible with NATO systems and expose F-35 jets to possible Russian subterfuge.
Turkey, however, stressed that the S-400s would not be integrated into NATO systems, and pose no threat to the alliance or its armaments.
Turkish officials have repeatedly proposed a working group to examine the technical compatibility issue.
Touching on Turkey's state lender Halkbank case, he said it is "not a matter for the US administration", adding: "The matter of the judicial proceedings in the Southern District of New York with respect to Halkbank case lies exclusively in the whelm of US courts."