President Vladimir Putin on Thursday threatened to strike "decision-making centres" in Kyiv with Russia's new hypersonic missile, hours after Moscow pummelled Ukraine's energy grid in an attack that left a million people without power.

President Vladimir Putin has threatened to target Kyiv's "decision-making centres" with a new ballistic missile. Questions have been raised about its potential impact and speed after it was used to attack the Ukrainian city of Dnipro last week.