Two months before the end of the heating season, all volumes of gas pumped last year were taken from Ukraine's storage facilities. By mid-February, the UGS occupancy rate may drop to 10%, when only limited volumes can be taken from storage facilities.

To wean itself off Russian natural gas, Europe has found new sources of energy, including imports from the United States. But high costs are straining the economy.

The European Commission will continue talks with Ukraine on natural gas supplies to Europe and will include Hungary and Slovakia in these talks, according to a statement shared by an EU diplomat and seen by Reuters on Monday.

Ukraine is ready to consider the possibility of cooperating with European operators on gas transit to the EU, but it is the European Commission that must decide whether the European side needs such transit and whether it is ready to provide it.