The Black Sea peninsula has been hit by power cuts after unknown attackers blew up pylons at the weekend, cutting power lines from Ukraine, which supplies most of its electricity.
The energy ministry in Moscow said that some 938,000 residents of Crimea remained without electricity and Russia was sending 300 mobile generators to the peninsula.
Energy minister Alexander Novak said Russia may shortly cut natural gas supplies to Ukraine because Kiev had not made an upfront payment and suggested Moscow could also cut coal deliveries.
Russia supplies around a third of Europe's gas, with roughly half of it flowing via Ukraine and has been involved in a festering pricing dispute with Kiev.
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Novak and Russian Emergencies Minister Vladimir Puchkov were expected to visit Crimea later Tuesday.
Ukraine on Monday halted the movement of goods to Crimea, ratcheting up tensions with Moscow amid a relative lull in fighting in separatist eastern Ukraine that has claimed more than 8,000 lives since April 2014.
Tensions have spiked as Kiev's landmark free-trade agreement with the European Union is set to come into force on January 1, 2016.
Kiev vowed on Monday to respond in kind.
Ukraine's interior minister even suggested that Kiev cut power supplies to Crimea altogether.
Crimea declared a state of emergency after an explosion Saturday in Ukraine's Kherson region bordering the peninsula cut the two working power lines heading to the territory, leaving some 1.6 million people without electricity.
The authorities in Crimea, which depends on Kiev for most of its power supplies, have suggested Ukraine was involved in the blast.
"Not only is Crimea suffering, but the Kherson region is also suffering, Ukraine's energy industry is suffering," Novak said.