Top national security agencies in a rare joint statement Tuesday confirmed that Russia was likely responsible for a massive hack of U.S. government departments and corporations, rejecting President Donald Trump’s claim that China might be to blame. The Associated Press reports: The statement represented the U.S. government’s first formal attempt to assign responsibility for the breaches at multiple agencies and to assign a possible motive for the operation. It said the hacks appeared to be part of an “intelligence-gathering,” suggesting the evidence so far pointed to a Russian spying effort rather than an attempt to damage or disrupt U.S. government operations. “This is a serious compromise that will require a sustained and dedicated effort to remediate,” said the statement, distributed by a cyber working group comprised of the FBI and other investigative agencies. Russia has denied involvement in the hack.