Russia may cut off gas to Europe entirely as it seeks to bolster its political leverage amid the Ukraine crisis, the head of the International Energy Agency said on Wednesday, adding that Europe needed to prepare now.

"Considering this recent behavior, I wouldn’t rule out Russia continuing to find different issues here and there and continuing to find excuses to further reduce gas deliveries to Europe and maybe even cut it off completely," IEA executive director Fatih Birol said in a statement sent to Reuters.

"This is the reason Europe needs contingency plans."