Kyiv is working with allies on security guarantees akin to NATO's mutual protection pledge, Ukraine's president Volodymr Zelensky has said. Officials from Ukraine and allies the U.S., the U.K., France and Germany met in London on Thursday in a week when a peace proposal was produced which outlined an Article 5-like agreement which would be backed by Washington.

The president’s comments came after he said Crimea “will stay with Russia,” a position backed by the mayor of Kyiv, who conceded that his country may have to give up territory.

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.