Russian forces have driven the Ukrainian army out of the biggest town in Russia's Kursk border region, officials claimed Thursday, as U.S. officials sought the Kremlin's response to a proposed 30-day ceasefire in the three-year war that Ukraine has endorsed.

President Vladimir Putin made a surprise visit to Russia’s occupied Kursk region on Wednesday, as the Kremlin considers a US proposal for a 30-day ceasefire with his troops closing in on Ukraine’s only territorial bargaining chip.

Kremlin forces have retaken the largest town in the Kursk region and expect roll back all Ukrainian gains in the area, the Russian defense ministry said.