Russia and Ukraine said they exchanged an unspecified number of sick and wounded prisoners of war on Tuesday under an agreement reached at peace talks last week in Turkey.

Russia's lead negotiator in peace talks with Ukraine warned on Monday that any deal that did not secure his country's lasting interests would ultimately result in "the end of the planet."

At least two civilians were killed and 60 wounded in a major overnight drone attack on Kharkiv, as both sides intensify drone warfare amid stalled peace talks.