The United States has formally determined that members of Russia's armed forces have committed war crimes in Ukraine, Secretary of State Antony Blinken announced in a statement on Wednesday as President Joe Biden travels to Europe to meet with allies about the ongoing conflict.

"Since launching his unprovoked and unjust war of choice, Russian President Vladimir Putin has unleashed unrelenting violence that has caused death and destruction across Ukraine," Blinken wrote. "We’ve seen numerous credible reports of indiscriminate attacks and attacks deliberately targeting civilians, as well as other atrocities. Russia’s forces have destroyed apartment buildings, schools, hospitals, critical infrastructure, civilian vehicles, shopping centers, and ambulances, leaving thousands of innocent civilians killed or wounded."

According to the United Nations human rights office, as of Wednesday, 977 civilians have been killed in Ukraine since Russia's invasion began nearly a month ago, including 81 children. The U.N. believes that "the actual figures are considerably higher."

"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 wrote. "Our assessment is based on a careful review of available information from public and intelligence sources."

"Many of the sites Russia’s forces have hit have been clearly identifiable as in-use by civilians," Blinken said, referencing an attack on a maternity hospital in Mariupol, as well as a theater in the besieged port city which had hundreds of people inside, including children.

The theater, Blinken said, was "clearly marked with the word 'дети' — Russian for 'children' — in huge letters visible from the sky."

"Putin’s forces used these same tactics in Grozny, Chechnya, and Aleppo, Syria, where they intensified their bombardment of cities to break the will of the people," Blinken continued. "Their attempt to do so in Ukraine has again shocked the world and, as President Zelenskyy has soberly attested, 'bathed the people of Ukraine in blood and tears.'"

The move comes after President Joe Biden accused Putin of war crimes at the White House last week, saying: "I think he is a war criminal."

It remains to be seen how Russia can be held accountable for its actions, if at all. Neither Russia nor the U.S. recognizes the authority of the International Criminal Court at The Hague, further complicating matters.

The U.S. could still assist a prosecution before the court, which earlier opened an investigation into atrocities committed in Ukraine, by helping to gather evidence against Russian forces in Ukraine, using some of the vast abilities it has deployed to track and monitor what has been happening in the conflict.

The U.S. could also provide support and backing to a commission of inquiry established by the U.N. Human Rights Council.

"As with any alleged crime, a court of law with jurisdiction over the crime is ultimately responsible for determining criminal guilt in specific cases," Blinken continued. "The U.S. government will continue to track reports of war crimes and will share information we gather with allies, partners, and international institutions and organizations, as appropriate. We are committed to pursuing accountability using every tool available, including criminal prosecutions."

The Associated Press contributed to this report.