The discrepancies between weekdays and weekends in Ukraine and the U.S., and the fall of the Russian ruble rate, may explain the temporary instability of the hryvnia over the past few days, Ukraine's Finance Minister Natalie Jaresko said.

"I am not in Kyiv, but I can imagine that there is some psychological effect from what is happening to the ruble in Russia, Jaresko told reporters on Friday at the Ukrainian Breakfast in Davos, Switzerland, organized by the Victor Pinchuk Foundation.

Jaresko said the demand and supply on Ukraine's forex market temporarily lost their balance due to the holidays, which led to a reduction of the national currency rate.

At the same time, the minister said there are no fundamental causes or decisions made by the Ukrainian authorities for such fluctuations.