Ukraine pumped 2.2 billion cubic meters (bcm) of natural gas into the Ukrainian underground storage facilities from January 1 to May 26, 2015, PJSC Ukrtransgaz's press service said.

"Thus, 9.8 bcm of gas is now stored in the Ukrainian underground storage facilities," the company said.

According to Ukrtransgaz, 1.37 bcm has been pumped since the beginning of May, and 0.820 bcm was pumped in April alone.

"According to preliminary reports, natural gas is accumulated in six gas storage facilities, 64 million cubic meters of gas is pumped into them on a daily basis," the company said.