Ukraine's gas debt to Russia will be almost $2 billion if the country fails to pay for February deliveries in full.
Speaking at a press conference, Russian President Vladimir Putin said that Ukraine's current debt stands between $1.5bn and $1.6bn.
Earlier, Russia's top gas producer Gazprom said it would remove a discount on gas prices for Ukraine starting from April.
More top news
Social media giant Facebook has bought the tbh app, launched only in August, which encourages teenagers to be friendly to each other.
Hillary Clinton appeared in a protective boot during a delayed TV appearance as she revealed how she suffered the injury.
Myeshia Johnson, who is pregnant with the couple's third child, was en route to meet her husband's body when Trump called.