Ukraine's energy minister has told the parliament in Kyiv that Russia has begun to restrict coal supplies to Ukraine, days after the Kremlin threatened to punish Kyiv for a power blackout of Russian-annexed Crimea.

Volodymyr Demchyshyn told lawmakers on November 27 that pro-Russian separatists who control coal mines in eastern Ukraine also have halted the delivery of coal supplies.

He said that with two ships carrying coal from South Africa due to arrive in December, Kyiv would have enough coal to "ensure the stable functioning" of its energy system for 45 to 50 days.

He said Ukraine was in talks with South Africa about further coal deliveries.

Russian Energy Minister Aleksandr Novak said on November 24 that Russia might cut coal supplies to punish Ukraine for what he said was its deliberate refusal to help rebuild power lines to Crimea that were blown up by unknown saboteurs.

Russia has already cut natural gas deliveries to Ukraine.

Demchyshyn said Ukraine had enough reserves to last through the winter.

Russia seized Crimea from Ukraine in March 2014, plunging relations between the onetime allies into crisis.

Based on reporting by Reuters, AP, AFP, and dpa