President Vladimir Putin said on Thursday that Russia had trapped the remaining Ukrainian soldiers in its western Kursk region, where they have clung on for more than seven months in one of the key battles of the war.

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.