After months of tense negotiations, the U.S. and Ukraine have signed a deal that is expected to give Washington access to the country’s critical minerals and other natural resources.

The joint economic investment between the U.S. and Ukraine comes after China restricted exports of some rare earth minerals to the U.S.

The agreement could provide a windfall to the U.S., but the resources will be expensive to extract, and any progress is unlikely while the war rages.