Director of National Intelligence James Clapper is the highest-ranking US official to publicly implicate Beijing since news of the data breach emerged.
China always dismissed suggestions that it was behind the hacking.
The statement comes after three days of high-level talks in which China and the US agreed to a “code of conduct”.
At a conference in Washington DC, James Clapper said: “China remains the leading suspects.”
“The US government continues to investigate” he added, according to his office.
At the Washington talks where cyber security was a top priority, Secretary of State John Kerry said there was a need to work with China to develop a “code of conduct” on state behavior in cyberspace – Chinese representatives had agreed with these conclusions.
“It’s something that we agreed needs to be addressed and hopefully it can be addressed soon,” State Department spokesman John Kirby said on June 25.
China has said any suggestion that it was behind the hacking is “irresponsible and unscientific”.
Image source: Wikimedia Commons President-elect Donald Trump celebrated his election victory at the Ultimate Fighting…
Millions of voters across the US chose to return Donald Trump to the White House…
Donald Trump declares victory in the US election as he addresses jubilant supporters in Florida.…
Stocks around the world are rising as Donald Trump appears to be on the cusp…
Donald Trump has won Pennsylvania, North Carolina and Georgia and taken a lead over Kamala…
Quincy Jones, the celebrated musician and producer who worked with Michael Jackson, Frank Sinatra, Ray…