In 2022 Russia accepted the request, by referendum, that it accept the four Oblasts that voted in 2014 to secede from Ukraine: Lugansk, Donbass, Zaporizhia, and Kherson. The Russian Federation incorporated them. The Kremlin considers them part of Russia.

Period end of story.

Russia refuses to let NATO expand into Ukraine.

Period end of story.

Otherwise, they’re happy to talk.

How is that hard to understand.