Turkey and US presidents Recep Tayyip Erdogan and Donald Trump held a bilateral meeting on the sidelines of the NATO summit in London, Anadolu News Agency reported on Wednesday.
The details of the negotiations are not disclosed.
Deliveries of the latest Russian air defense systems, the C-400, which triggered a crisis in Turkey-US relations, began in mid-July. According to Turkish President, the C-400 will be fully operational in April 2020. Washington has demanded the deal to be canceled, threatening to delay or even cancel the sale of the latest F-35 fighter jets in Turkey, and impose sanctions in accordance with the CAATSA (Countering America's Adversaries Through Sanctions Act).
Ankara refused to make concessions.