Close to 200,000 Russian troops have been killed or wounded in the war in Ukraine, according to estimates from U.S. and European officials, a toll that is likely to continue to rise as the Kremlin readies a fresh offensive in the coming weeks.

The U.S. military, which keeps rough estimates on Russian casualties in Ukraine, puts the figure for wounded and dead at roughly 180,000, though officials stressed such figures aren’t precise, a U.S. defense official said.

The tally matched assessments by Norway’s defense chief Gen. Eirik Kristoffersen, who said last week that the number of Russian soldiers killed or injured was approaching 180,000. Mr. Kristoffersen estimated that 100,000 Ukrainian soldiers have been killed or wounded, in line with an estimate Pentagon officials put out in November.

The casualty count comes as Moscow’s forces press an eastern offensive in an effort to seize the advantage on the battlefield before tanks pledged by Kyiv’s allies begin to arrive in Ukraine and as the conflict approaches its one-year mark on Feb. 24.