Russian energy company Gazprom said it has "stopped supplying un-paid-for gas to Ukraine" this morning, according to reports in Russian media.
Gazprom said Ukraine has failed to pay for its gas supplies.
A Gazprom spokesperson told ITV News the company will now require all payments to be made in advance.
More top news
It will be hotting up as we approach the weekend as we draw in very warm air from the Continent - it'll feel more like summer than spring.
A new scam aimed at people who own Apple iPhones steals their account information through a text.
Tomorrow’s Congress is expected to be dominated by claims of North Korea’s nuclear prowess.