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.

U.S. President Donald Trump and Ukrainian leader Volodymyr Zelenskiy, in Rome for the funeral of Pope Francis, met one-on-one in a marble-lined Vatican basilica on Saturday to try to revive faltering efforts to end Russia's war with Ukraine.

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.

Russian President Vladimir Putin has claimed that his country has regained control of Kursk, the border region where Ukraine launched a surprise offensive last year, though Ukraine’s army says fighting continues.

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 Russia’s Kursk region, Kremlin spokesperson Dmitry Peskov said Saturday. Ukrainian officials have not commented on the claim.