Russian President Vladimir Putin has cast doubt on the feasibility of a U.S.-proposed 30-day ceasefire in Ukraine, arguing that such a truce could provide Kyiv with an opportunity to regroup and acquire additional military aid from the West.

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.

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.