Ukrainian President Volodymyr Zelenskyy has accused Russia of striking energy infrastructure in the southern region of Odesa with Iranian drones, causing a massive blackout.

In a video message on Saturday, Zelenskyy said, "The situation in Odesa region is very difficult. After the night strike by Iranian drones, Odesa and other cities and villages of the region are in the dark." He went on to say that more than 1.5 million people in the region were without electricity.

Zelenskyy claimed that Russia had used 15 drones against Odesa over one night. He said, "This is the true attitude of Russia towards Odesa, towards Odesa residents." He called Russia's actions "deliberate bullying" and "deliberate attempt to bring disaster to the city."

The US government says its intelligence analysis shows that Russia and Iran are considering setting up a drone assembly line in Russia. US officials also say Russia may be providing Iran with helicopters and air defense systems, in return for drones.

The US and European countries are wary of the deepening military ties between the two countries.