The Kremlin said on Thursday that Moscow was worried by talk of a road map for Ukraine to join NATO and described the "problem" of the military bloc as one of Russia's "red lines".

Axar.az reports citing foreign media that Kremlin spokesman Dmitry Peskov made the remarks a day after the presidents of Russia and the United States met for a summit in Geneva. He said those talks had been positive overall.

Speaking on Ekho Moskvy radio station, Peskov said Moscow and Washington shared an understanding of the need to talk about arms control as soon as possible. He also said Russia's ambassador would return to Washington soon.