No breakthroughs in Ukraine-Russia talks; UN says over 4 million Ukrainians have fled

Kremlin spokesperson Dmitry Peskov said Wednesday it was "positive that Ukraine has formulated specific proposals at the talks in Istanbul but also added that there are no breakthroughs.

"There is still a very, very long work to be done," he added.

On Ukraine's proposal to discuss the status of Crimea over the next 15 years, Peskov said there was nothing to discuss as "Crimea is part of the Russian Federation".

"According to our constitution, we cannot discuss with anyone the fate of the territory of the Russian Federation," he said.

Asked about the switch to rubles in payments for gas starting Thursday, Peskov said this was not going to happen in a single day.

On the proposal of State Duma chairman Vyacheslav Volodin to switch the payments for other commodities to rubles, he said that the idea, "of course, should be worked out" and added that switching to national currencies is a natural process, as the prestige of the US dollar had been eroded.