Citing US officials with knowledge of the matter, US media indicated that the United States believes one of Ukraine’s special military or intelligence units carried out the attack, but that investigators are not sure exactly which unit orchestrated the attack.
US insiders stated it remains unclear for them whether Ukrainian President Volodymyr Zelensky was aware of the operation, although some officials believe he was not.
The agencies’ preliminary assessment was based on intercepted communications from both Russian officials, who pinned responsibility for the attack on Ukrainian officials, who likewise said they believed Kiev was behind the operation.
The US officials’ confidence in their assessment that Ukraine was behind the attack is "low" due to a lack of specific evidence identifying the involved parties, the report said, adding that the attack appears to be one of a number of operations by Ukraine that have worried American officials.
US intelligence agencies reportedly believe certain Ukrainian units are able to conduct limited operations inside Russia.