ISW: Russians didn't make confirmed advances in Siversk dir

https://understandingwar.org/research/russia-ukraine/russian-offensive-campaign-assessment-december-12-2025/

Russian forces continued offensive operations in the Siversk direction on December 12 but did not make confirmed advances.

Key Takeaways

1. Ukrainian forces recently liberated territory including part of the city of Kupyansk in a tactical counterattack in the Kupyansk direction.
2. This Ukrainian counterattack demonstrates that Ukrainian forces remain capable of defending and counterattacking against significant Russian offensive efforts, contrary to the claims of Russian President Vladimir Putin that the Ukrainian lines are collapsing.
3. The contours of the Ukrainian counterproposal to the most recent US peace proposal are emerging, but details of this counterproposal remain unclear.
4. The Kremlin explicitly rejected Ukraine’s proposals for a ceasefire and referendum.
5. The Kremlin rejected the Ukrainian offer to establish a demilitarized zone.
6. The European Union (EU) agreed on December 12 to indefinitely freeze 210 billion euros (roughly $247 billion) in Russian assets to provide Ukraine with a reparations loan of up to 165 billion euros (roughly $194 billion).
7. Ukrainian forces recently advanced near Kupyansk and Oleksandrivka. Russian forces recently advanced in the Kostyantynivka-Druzhkivka tactical area and near Hulyaipole.