Russia’s president, Vladimir V. Putin, dressed in fatigues, visited a command post near the front in Kursk late Wednesday to cheer on his military’s ejection of Ukrainian forces from much of the territory they had been occupying in the Russian border region.

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.