Ukraine's natural gas reserves in its massive underground storage tanks have fallen to a critical level and the country urgently needs to import more gas, said Serhiy Makogon, the former head of Ukraine's gas transit operator Gas Transmission System Operator of Ukraine (GTSOU), reports Reuters on January 29.

Gas in the storage facilities are nearing the 10% threshold, a technical minimum for gas tanks after which the pressure becomes so low the gas becomes increasingly difficult to withdraw from the tanks.

Makogon called for more imports to start immediately to avert a potential energy crisis, as the heating season will continue until the end of March.

The decline in gas reserves comes at an awkward time, following on from Ukraine’s decision to not renew a gas transit deal with Russia on January 1, halting flows of Russian gas through the country.

At the same time, a Russian missile barrage targeting Ukraine’s energy infrastructure that began last March has destroyed about half of Ukraine total installed power and heating capacity, leading to rolling blackouts and freezing temperatures in homes.

Ukraine produces around 20bn cubic metres of gas per year, not quite enough to cover domestic demand, and relies on its allies in the West to provide it with top-ups. Ukraine started this heating season with some 13 bcm of gas in its reserve tanks, which was thought to be adequate at the time, but this winter has proved to be colder than expected. Europe is also using up its stored gas faster than on average, but analysts believe it has enough in reserve to get through the winter.

The situation is further complicated by the cancellation of a scheduled meeting between Slovak, Ukrainian, and European Commission officials concerning gas supplies. The meeting, planned for early January, was called off due to Kyiv's failure to confirm its participation, leaving regional energy cooperation efforts in limbo, Reuters reports.