NEW YORK, December 20. /TASS/. White House officials planned to make a statement alleging that Russia had been involved in the hacker attack against computer systems of the US government but were instructed at the last minute not to release it, The Associated Press news agency reports, citing a source.

"Officials at the White House had been prepared to put out a statement Friday afternoon that accused Russia of being "the main actor" in the hack, but were told at the last minute to stand down, the news agency says, citing a US official familiar with the conversations who spoke on condition of anonymity.

"This is looking like it’s the worst hacking case in the history of America," the official said.

Reuters reported Monday that a group of hackers allegedly working for Russia carried out a cyberattack on December 13 to obtain unauthorized access to computer systems of the US Department of Homeland Security. The department itself confirmed that cyberattack had taken place. According to Reuters, the hackers got their hands on data from the Department of State and the Pentagon.

Russian presidential spokesman Dmitry Peskov earlier dismissed US allegations Russian hackers were behind those cyberattacks.