Slovenia's natural gas supply has decreased by one third because of the Russian-Ukrainian dispute over natural gas deliveries, Slovenian gas company Geoplin said in Ljubljana on Monday.

Geoplin said in a statement that it could ensure delivery without any problems if the air temperature does not drop under minus six degrees Celsius, the Slovene Press Agency reported.

If however the temperature does drop and if the supply were reduced by more than a third, the customers would be asked to minimize the use of natural gas, said the statement.

The drop in gas supply is a result of a Russian-Ukrainian dispute over natural gas prices, because of which the Russian state-run gas monopoly Gazprom stopped delivering natural gas to Ukraine. Gazprom supplies about a half of the EU's gas and 80 percent of Gazprom's Europeans exports pass through Ukraine.

The dispute has also influenced gas deliveries in other EU countries, which receive Russia's gas through Ukraine, although Gazprom has said that supplies to Europe would not be affected.