Secretary of State Marco Rubio got into a testy exchange with a congressman on Wednesday after he repeatedly refused to directly call Russian President Vladimir Putin a war criminal.

It happened during a House hearing when Maryland Democratic Rep. Bill Keating asked Rubio about Putin’s involvement in war crimes against Ukraine.

The hearing comes at a time when the Trump administration is attempting to broker a ceasefire between Russia and Ukraine ― despite failing to get Putin to make any move that would lead to that result.

Things got testy after Keating directly asked the secretary of state, “The person we’re negotiating with, Vladimir Putin, is he a war criminal?”

Rubio tried to answer the question without actually answering the question.