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.

A Ukrainian drone attack has destroyed more than 40 Russian planes deep in Russia’s territory, Ukraine’s Security Service said on Sunday, while Moscow pounded Ukraine with missiles and drones just hours before a new round of direct peace talks in Istanbul.

Speaking at a separate news briefing, Russian delegation head Vladimir Medinsky confirmed all sick and heavily wounded prisoners of war, as well as those younger than 25, would be exchanged. No timeframe was given as to when this would happen.

Zelenskiy told an online news briefing that negotiators for Russia and Ukraine agreed to exchange 1,000 prisoners each, with the possibility of swapping an additional 200 POWs. He said there was also agreement to return the remains of killed service personnel,

Russia and Ukraine said they had agreed at peace talks on Monday to exchange more prisoners of war and return the bodies of 12,000 dead soldiers.