VIDEO-Russian Hackers Accessed Sensitive Parts of White House Computer Network, CNN Reports |

Russian hackers were able to access sensitive parts of the White House computer system, including President Barack Obama’s real-time schedule with details not available to the public, CNN reported Tuesday, citing sources.

U.S. officials briefed on the investigation told the news outlet that the hackers were able to break into the system using a perch from a previous cyber attack on the State Department.

The White House is seen through a keyhole in the fence, Tuesday, Aug. 27, 2013, in Washington. (AP Photo/Jacquelyn Martin)

Deputy national security advisor for strategic communications told CBS News White House correspondent Mark Knoller that the agency does not confirm cyberintrusions.

He added that the White House computer systems are secure and told CNN authorities do not believe sensitive national-security documents were stolen.

“We do not believe that our classified systems were compromised,” Rhodes told CNN.

“We’re constantly updating our security measures on our unclassified system but we’re frankly told to act as if we need not put information that’s sensitive on that system,” he added. “In other words, if you’re going to do something classified, you have to do it on one email system, one phone system. Frankly, you have to act as if information could be compromised if it’s not on the classified system.”

Follow Oliver Darcy (@oliverdarcy) on Twitter