Expert Mark Galeotti told Newsweek that both sides in the Russia-Ukraine war have been boosting their efforts "to gather whatever information they can."

Russian President Vladimir Putin vowed Monday to achieve all his "goals" in Ukraine and celebrated the second anniversary of annexing four Ukrainian regions, as his army claimed fresh advances in the conflict.

President Vladimir Putin warned the West on Wednesday that Russia could use nuclear weapons if it was struck with conventional missiles, and that Moscow would consider any assault on it supported by a nuclear power to be a joint attack.