Nearly 1 million Russian soldiers have been killed or injured in the country’s full-scale invasion of Ukraine, according to a new study, a grisly measure of the human cost of Russian President’s Vladimir Putin’s unprovoked three-year assault on its neighbor.

Russia will likely surpass 1 million casualties in its war on Ukraine this summer, according to one of the world’s leading think tanks.

Moscow has a small number of soldiers in Transnistria, which has been controlled by separatists in a frozen conflict for 33 years. With the conclave landlocked between Ukraine and a pro-EU government in Moldova, however, Russia is currently unable to send more troops there.