Ukraine had hoped it could use the land it had seized in the Kursk region as a bargaining chip in future peace talks with Russia, which launched its full invasion in 2022 and has currently controls around 20% of Ukraine's internationally-recognised territory.

All Ukrainian troops have been forced from parts of Russia’s Kursk region, which Moscow lost control of last year to a surprise Ukrainian incursion, Russia’s top general said in a Kremlin meeting Saturday.

The leaked American ceasefire proposal would end sanctions on Russia, freeze the front line and see America formally recognise Russia’s annexation of Crimea. The intelligence officer, based in Kyiv, does not hide his disdain.