The U.S. government formally—and finally—admitted to killing four American citizens today, one day before President Obama is set to deliver an important speech on national security and counterterrorism issues.

In a letter addressed to leading members of Congress, which was later obtained by the New York Times, embroiled Attorney General Eric Holder revealed that the Obama administration had intentionally killed hardline Muslim cleric Anwar al-Awlaki with a 2011 Yemeni drone strike.

The letter went on to acknowledge that U.S. drone strikes had also killed Samir Khan, who was killed with al-Awlaki; Abdulrahman al-Awlaki, al-Awlaki's 16-year-old son; and 22-year-old Jude Mohammad—though Holder specified that those three "were not specifically targeted by the United States."

The Obama administration's decision to execute al-Awlaki with drones has been one of the largest and most widely reported stains on its record, but the government had previously refused to confirm or deny its role in his death.

[Image via AP]