Ukraine controls more than 100 major deposits of critical minerals, according to a study by the Kyiv School of Economics, along with modest oil and natural gas reserves.

Ukraine has agreed to the terms of a deal that would allow the U.S. access to the country's rare earth and critical minerals reserves.

On snow-covered fields in central Ukraine, where some of the country's biggest proven lithium deposits are located, a small team of ecological consultants drop sensors into holes in the earth to measure water levels.