Ukraine shocked the world with its bold offensive operation in the summer that at its height took control of an area about the size of Los Angeles in Kursk, Russia.

Russian President Vladimir Putin has called on Ukrainian troops in the Russian region of Kursk to surrender, as diplomatic back-and-forth continues over a potential US-brokered ceasefire with Ukraine.

Ukrainian officials have not confirmed a retreat from the town in Russia’s Kursk region, parts of which were captured by Kyiv’s forces last summer.

Russian forces have recaptured Sudzha, the largest town that Ukraine once occupied in the Kursk region, according to Moscow, threatening Kyiv’s sole territorial bargaining chip amid pressure to negotiate an end to the war.