The U.S. Department of State said it is “concerned” by the filing of criminal charges against Georgia’s ex-president Mikheil Saakashvili.

“Commitment to the rule of law means both that everyone must comply with the law in a democratic society and that the legal system should not be used as a tool of political retribution,” reads the statement released on July 29.

“We are monitoring this and related cases closely, and continue to stress to Georgian officials the importance of rigorous adherence to due process and the rule of law,” Department of State said.