Vladimir Putin is leaving for Kiev today on a two-day visit.
Prikhodko stressed that "the theme of the joint use of Kerch Strait has been exhausted to mutual satisfaction".
But "the resolution of the problem of the border in the Azov-Kerch water area will take time", Prikhodko noted. In his opinion, "this will take at least two years".
"The most important thing is that this process should not be politicized", the deputy head of the Kremlin administration stressed.
He cited "the situation of the Russian language" among the questions which have not been solved yet in relations between Russia and Ukraine". He noted that the number of Russian schools keeps diminishing in Ukraine.
"The main thing the Russian side strives for is that the Russians living in Ukraine, and the Ukrainians living in Russia should feel comfortable, and have a chance to meet their linguistic and cultural requirements", Sergei Prikhodko said .