Secretary of State Antony Blinken released a statement officially confirming Russia has committed war crimes during its invasion of Ukraine. President Joe Biden had already called Russian President Vladimir Putin a war criminal last week, with Blinken announcing a day later that the State Department was “compiling the evidence, collecting the evidence, understanding the evidence” of war crimes.

“Today, I can announce that, based on information currently available, the U.S. government assesses that members of Russia’s forces have committed war crimes in Ukraine,” Blinken said in Wednesday’s statement. “Our assessment is based on a careful review of available information from public and intelligence sources.”

While Blinken noted that “Putin has unleashed unrelenting violence that has caused death and destruction across Ukraine,” he focused on the city of Mariupol in his statement Wednesday.

“Many of the sites Russia’s forces have hit have been clearly identifiable as in-use by civilians,” Blinken said. “This includes the Mariupol maternity hospital, as the UN Office of the High Commissioner for Human Rights expressly noted in a March 11 report. It also includes a strike that hit a Mariupol theater, clearly marked with the word ‘дети’ — Russian for ‘children’ — in huge letters visible from the sky.”

At a State Department briefing Wednesday, the department’s ambassador at large for global criminal justice said while it will be up to “a court of law to determine individual criminal responsibility” for any war crime, the U.S. will use “all of the tools that are available to us” in “pursuing full accountability for war crimes in Ukraine.”

“The US government will continue to track reports coming out of Ukraine of war crimes, and we will share this information with our friends and allies and with international and multilateral institutions as appropriate,” Beth Van Schaack said. “We are also supporting the Ukrainian Prosecutor General’s Office and their War Crimes Directorate and supporting civil society documentation efforts.”

Neither Russia nor the U.S. recognizes the authority of the International Criminal Court at The Hague, which could make seeking accountability difficult. In addition to gathering evidence, the U.S. could also support a commission of inquiry established by the U.N. Human Rights Council.