Russian representatives asked their American counterparts during negotiations held in Riyadh on Monday for clear guarantees so that the Kremlin authorities would allow the resumption of commercial traffic in the Black Sea to and from Ukraine, Sergey Lavrov, the Minister of Foreign Affairs of the Russian Federation, said yesterday in an interview with the television station PervĂŽi Kanal (Channel 1). "As agreed in the recent telephone conversation between Presidents Putin and Trump, issues