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.

The American visit comes as President Vladimir Putin visited Russia's Kursk region - parts of which have been under Ukraine's control since an incursion last year. Russian TV aired footage of Putin meeting military commanders, who told him Russian troops had recaptured 86% of the area from Ukraine.