National JSC Naftogaz Ukrainy may transfer prepayment for about 1 billion cubic meters (bcm) of natural gas to Russia's OAO Gazprom by the end of the current week amid an increased demand for energy supplies due to the frosty weather, Ukrainian Energy and Coal Industry Minister Yuriy Prodan said.

"[This is the] payment for the purchase of about 1 bcm," he told reporters in Kyiv on Tuesday.