The White House is declining to name the source of a hack to its unclassified e-mail system amid reports that it came from Russia.
"At this point our investigators have concluded that it's not in our best interest to identify the entity," White House Press Secretary Josh Earnest said on April 8.
Earnest said the timing of the hack in October -- when Moscow and Washington were working on Iranian nuclear negotiations -- is "an indication of the kind of complicated relationship we have with Russia."
CNN and Bloomberg reported that U.S. officials believe Russia was behind the attack that also affected the State Department.
Russian President Vladimir Putin's spokesman, Dmitry Peskov, dismissed the report, saying that "Russia is blamed for everything."
U.S. officials say the October cyberattack against the government did not compromise the White House's classified network systems.