Russia's energy giant Gazprom started to supply natural gas to southeastern Ukraine Thursday afternoon as Kiev cut off gas supplies to the war-torn areas the day before.

"In line with the current contract between Gazprom and Naftogaz (the Ukrainian national energy firm), we delivers to Ukraine 12 million cubic meters of gas on a daily basis starting from 4:00 p. m. Moscow time (1300 GMT)," the Gazprom CEO Alexei Miller said.

Earlier in the day, Russian Prime Minister Dmitry Medvedev ordered the Ministry of Energy and Gazprom to prepare proposals for humanitarian gas supplies to the southeastern Ukraine, where Donetsk and Lugansk regions are located.

Meanwhile, the prime minister ordered the Russian Emergency Ministry to deliver food and medicines to the two Donetsk and Lugansk regions, including the embattled transport hub of Debaltseve.

At 3:00 p.m. Wednesday local time, Kiev cut off its gas supplies to the regions, seen by the rebels as a political move.

"By cutting off gas, Kiev is escalating tensions and trying to spread panic. This is political and economic pressure," Gennady Tsypkalov, prime minister of the self-claimed Lugansk People's Republic, was quoted as saying by the TASS news agency.

The natural gas reserves in the southeastern Ukrainian regions were exhausted 24 hours after Kiev cut off the delivery.