The issue of a halt in imports of Russian oil and gas has been at the top of the EU's political agenda.

But the question is complicated - as many countries are dependent on Russia's large deposits of fossil fuels.

The country accounts for about six percent of the world's known oil deposits to date.

In 2016, it corresponded to about 60 years of oil left, if you count the country's then annual consumption, according to the statistics site Worldometer.

It can be compared to the USA which had the equivalent of 5 years of oil left.

How did plankton and algae on the seabed become decisive in World War II?

See a summary of the oil's bloody history in the clip.