U.S. President Joe Biden speaks on renewable energy at the Philly Shipyard on July 20, 2023 in Philadelphia, Pennsylvania.
CNN  — 

President Joe Biden has decided to allow the US to cooperate with the International Criminal Court’s investigation of Russian war crimes in Ukraine, two US officials and a source familiar with the matter told CNN.

The decision comes after months of internal debate and marks a historic shift, as it would be the first time the US has agreed to share evidence with the court as part of a criminal probe into a country that is not a member of the ICC. Neither the US nor Russia are members of the court.

“It could be deeply consequential,” one of the sources said, adding that the US government now has “a clear green light” to share information and evidence with the ICC.

What information the US shares will ultimately depend on what the ICC prosecutor requests for the investigations, the source explained.

A National Security Council spokesperson would not comment directly on the decision, but said in a statement that Biden “has been clear: there needs to be accountability for the perpetrators and enablers of war crimes and other atrocities in Ukraine.”

“We have been clear that we support a range of international mechanisms to identify and hold accountable those responsible, including through the Office of the Ukraine Prosecutor General, the Joint Investigative Team through Eurojust, the United Nations Human Rights Monitoring Mission, the Expert Missions established under the OSCE’s ‘Moscow Mechanism,’ and the International Criminal Court among others,” the spokesperson added.

The New York Times first reported on Biden’s order.

On Friday, Ukrainian Prosecutor General Andriy Kostin praised the US decision, calling it “another historic stride towards building comprehensive accountability for Russia’s international crimes.”

Kostin gave “heartfelt thanks” to Attorney General Merrick Garland and the US Justice Department “for standing with Ukraine at the frontline of justice.”

“Once again, we see that commitment, unity, and persistence yield fruitful results,” Kostin wrote on Twitter. “Every meeting, letter, and hearing at Congress brings us closer to our ultimate goal—halting Russia and holding Kremlin’s criminal regime accountable for all its atrocities.”

Over the course of the war, Biden administration officials have obtained evidence of alleged Russian war crimes in Ukraine, through intelligence gathering mechanisms among other channels, officials told CNN. But the administration debated for months internally over whether to share that evidence with the court, as officials grappled with the possibility that doing so could set a precedent that could one day be used against the United States, officials explained.

The Pentagon was the most concerned about cooperating with the court, officials said, and worried that doing so might set a precedent for the ICC to investigate alleged war crimes carried out by Americans in Iraq. Secretary of Defense Lloyd Austin raised his concerns with the president earlier this year, but told CNN’s Wolf Blitzer earlier this month that the Defense Department would cooperate with whatever policy decision was made by the president.

The NSC spokesperson noted that the US has already “deployed teams of international investigators and prosecutors to assist Ukraine’s Office of the Prosecutor General in documenting, preserving, and preparing war crimes cases for prosecution, and the Department of Justice has entered into a Memorandum of Understanding to cooperate with Ukraine on investigations and prosecutions of war crimes committed during Russia’s invasion of Ukraine.”