The United States is “deeply concerned” about a meeting between a top UN official for children and Russia’s ombudsman for children’s rights, who is sought after by the world’s permanent war crimes court, according to State Department spokesman Matthew Miller.

Maria Lvova-Belova, who is charged with a war crime by the prosecutor of the International Criminal Court for sending hundreds of Ukrainian children to Russia, claimed last week on her website that she met with Virginia Gamba, the UN secretary-general’s special envoy for children and armed conflict, in a working meeting.

“We are deeply concerned that a senior UN diplomat met with a fugitive subject to an ICC arrest warrant for committing war crimes against children,” Miller said at a press briefing. “Such conduct undermines our shared commitment to protecting children in conflict zones.”