Russia's latest missile attack on Ukraine hit energy infrastructure used to supply the European Union with natural gas, Ukrainian President Volodymyr Zelenskyy said.

Ukraine's energy system was struck by 34 Russian rockets in a "massive missile attack" on Saturday, Zelenskyy said in a video posted on X on Saturday evening.

The attack targeted "the power grid and the gas transit system, particularly the gas infrastructure that ensures the security of deliveries to the EU," the president said.

Russia has intensified its assaults against Ukrainian power stations in recent weeks, and its missiles are now also hitting gas storage facilities that were used by some EU companies last winter to prevent energy shortages.

Four thermal power plants were hit in Saturday's strikes, injuring one worker from Ukraine's biggest private energy company, DTEK, the firm said in a statement.

Ukraine's air force said it destroyed 21 out of the 34 Russian missiles in Saturday's attack.

In his short video address, Zelenskyy repeated a plea to Kyiv's allies to further strengthen Ukraine's air defenses, including Patriot air defense batteries which it says it crucially needs to protect Ukrainian cities and infrastructure against Russian strikes.

Germany has been pressuring other EU allies to redeploy their Patriot batteries to Ukraine. Last week, Greek Prime Minister Kyriakos Mitsotakis said his country wouldn't do so, because the batteries were "critical to our deterrent capability" against Turkey.