A bipartisan group of U.S. senators introduced legislation to designate Russia as a state sponsor of terrorism over the abduction of nearly 20,000 Ukrainian children during its invasion.

The bill aims to punish Moscow economically and pressure it to return the children.

Senators Lindsey Graham, Richard Blumenthal, Katie Britt, and Amy Klobuchar criticized Russia’s actions as crimes against humanity and emphasized that returning the children is a prerequisite for peace talks.

The proposal initially considered including Belarus but postponed it due to recent political developments, the New York Post has reported.

The senators are also pursuing broader sanctions against countries continuing to buy Russian oil.