The United States' top spy official said Thursday China is the "leading suspect" in the investigation into the massive cyber theft of U.S. federal employee data.
The comments by Director of National Intelligence James Clapper represent the first time a U.S. official has pointed a finger at China for the data breach.
"You have to kind of salute the Chinese for what they did," Clapper told an intelligence conference in Washington, referring to the difficulty of the operation.
A later statement by Clapper's office confirmed the comments, while stressing "the U.S. government continues to investigate" the hack.
The U.S. has not openly accused the Chinese government of being behind the digital attack on the Office of Personnel Management, but various officials have said they are increasingly convinced this is the case.
The U.S. has blamed China for a series of high-profile cyberattacks on U.S. government and business entities in recent years. China has strongly rejected the allegations.
Clapper said Thursday such attacks on U.S. targets are likely to continue as long as Washington fails to come up with sufficient deterrents.
White House Press Secretary Josh Earnest said the investigation is ongoing and that it is too early to speculate about a possible response.
Federal Bureau of Investigation officials believe as many as 18 million current, former and prospective federal employees were affected by the data breach.
The hackers are believed to have accessed not only basic personnel information, but also extremely sensitive data found in federal background checks.
Senior U.S. and Chinese officials this week held three days of talks in Washington where the issue of cybertheft was expected to be discussed.
Secretary of State John Kerry said the U.S. made it "crystal clear" that cybertheft was not acceptable, but did not go into the specifics of the conversation related to the OPM hacking.
"There was an honest discussion—without accusations, without any finger-pointing—about the problem of cybertheft and whether or not it was sanctioned by government or whether it was hackers and individuals that the government has the ability to prosecute," he said.
