Russia's announcement came as Ukrainian President Volodymyr Zelenskyy said his country would “have to respond in any way we can” to Russian attacks. Moscow has aggressively attacked Ukrainian energy sites ahead of and during winter throughout the more than four-year war. Key points and original sources are listed below.

• Russia's announcement came as Ukrainian President Volodymyr Zelenskyy said his country would “have to respond in any way we can” to Russian attacks.S1

• Moscow has aggressively attacked Ukrainian energy sites ahead of and during winter throughout the more than four-year war.S2