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.

President Trump and President Vladimir V. Putin both claimed that Ukrainian forces were surrounded. Ukraine’s top military commander vowed to “hold the line.”

U.S. President Donald Trump urged Kremlin leader Vladimir Putin on Friday to spare Ukrainian troops that Russia is pushing out of its Kursk region, an appeal Putin said he would honor if they surrendered.