In an operation said to be 18 months in the planning, Ukraine conducted a devastating series of drone strikes against Russia air bases on Sunday.

Though the knock-on effects are unclear, some military commentators have called the strike Russia's "Pearl Harbor." Hopes for direct peace talks, which resume Monday, remain low.

Vladimir Putin is set to dismiss his intelligence chiefs following a catastrophic security breach, which led to Ukraine taking out 41 aircraft worth £1.5billion across multiple airbases. The Russian leader has been conspicuously absent from public view since Ukraine's successful strikes,

By making harsh, uncompromising demands in peace talks with Ukraine while continuing to pummel it with waves of missiles and drones, Russian President Vladimir Putin is sending a clear message: He will only accept a settlement on his terms and will keep fighting until they’re met.

Russia has proposed another attempt at peace negotiations with Ukraine on Monday in Istanbul, but both sides remain firmly entrenched in positions likely to prolong the war.

Dozens of Russian military aircraft have been destroyed in an unprecedented drone attack deep inside Russia, a Ukrainian official has said, the day before critical peace talks between Moscow and Kyiv resume in Istanbul.

Vladimir Putin's Russia was attacked by Ukraine in shocking cross-border drone strikes deep into the Russian territory targeting key military installations.

Retired U.S. military leaders reacted on Sunday after Ukraine carried out a large-scale drone attack on Russian military aircraft deep inside the country, with one quipping that Russian President Vladimir Putin is "having a very bad day.