Russia says it has captured the town after a months-long battle, but Ukraine says fighting is ongoing.

As Russia's invasion of Ukraine enters its 11th month, US and Ukrainian officials tell CNN that Russia's artillery fire is down dramatically from its wartime high, in some places by as much as 75 percent.

The US Treasury on Friday imposed sanctions on officials tied to an Iranian defense manufacturer that designs and produces drones which have been used by Russia in the war in Ukraine, as well as the director of "the key organization responsible for overseeing Iran's ballistic missile programs."

A unilateral ceasefire called by Russia breaks down within hours of coming into effect.

Parts made by more than a dozen US and Western companies were found inside a single Iranian drone downed in Ukraine last fall, according to a Ukrainian intelligence assessment obtained exclusively by CNN.

Air raid sirens sounded shortly before midnight as the latest in a wave of attacks by Russia over the New Year period began.