Ukrainian and US officials held a "productive and efficient" round of talks in Riyadh on Sunday, aimed at de-escalating the war with Russia, Ukrainian Defense Minister Rustem Umerov says. "We discussed with our American partners very important issues, including free navigation and a ceasefire at sea and in the air. We touched on electricity, utilities, energy, and infrastructure ceasefire. We also discussed the humanitarian track, including the exchange of prisoners of war and civilians," Umerov added. SOUNDBITES