Ukraine will accumulate about 14.5 billion cubic meters (bcm) of gas in underground storage by the start of the heating season, exclusively using gas imported from Europe, Naftogaz Ukrainy CEO Andriy Kobolev said on Channel 5 television on Thursday.

"Since we understood there is the likelihood of a rejection from Gazprom in the third quarter, the gas purchasing schedule was constructed so that we could purchase gas fully, the entire volume necessary for Ukrainian consumers, from the European direction, which we began doing back in July," he said.

Ukraine is intensively buying gas in Europe using funds from the European Bank for Reconstruction and Development (EBRD) and its own money. "We are a little ahead of schedule, since private companies, not just Naftogaz, are buying gas. The daily imports are very high - about 45-46 million cubic meters. That is higher than any day last year. We reckon to accumulate about 14.5 bcm by the start of the heating season, which is a comfortable level for proceeding through the fall-winter season," he said.

Purchasing gas is currently impossible due to the "noncommercial behavior" of the Russian gas giant.

"The problem is that Gazprom refused to sign a supplementary agreement for the third quarter, which is absolutely necessary in order for deliveries to be made. It is not even a question of price. Gazprom signed such agreements at least three times: gas was supplied under them in 2014-2015, the summer of 2015 and last winter. This time, Gazprom unexpectedly refused, which we consider to be a manifestation of hostile and noncommercial behavior," Kobolev said.