US Secretary of State Antony Blinken will publicly announce the determination, which human rights groups have been advocating for years, at the US Holocaust Memorial Museum in Washington, DC, on Monday.
Until now, the US had stopped short of declaring the atrocities -- including mass killings and rape -- committed in 2017 against the Muslim minority Rohingya population a genocide. The violence forced nearly a million people to flee, and the United Nations recommended that top military officials face genocide charges.
"I applaud the Biden administration for finally recognizing the atrocities committed against the Rohingya as genocide. While this determination is long overdue, it is nevertheless a powerful and critically important step in holding this brutal regime to account," Democratic Sen. Jeff Merkley, a member of the Senate Foreign Relations Committee, said in a statement Sunday.
America, the Oregon Democrat said, "must lead the world to make it clear that atrocities like these will never be allowed to be buried unnoticed, no matter where they occur."
This story has been updated with comments from Sen. Jeff Merkley.