The Chinese foreign ministry on Thursday urged the United States to stop “fabricating stories” and “mudslinging” after a Federal Bureau of Investigation (FBI) official accused China of stealing secrets from U.S. firms.

“Chinese laws forbid hacking or any other behavior harmful to cyber security, and it is an undoubted fact that the Chinese government resolutely cracks down on crimes,” foreign ministry spokesman Hong Lei said at a daily news briefing in response to a question on the FBI official’s remarks.

FBI director James Comey said Sunday during a TV appearance that China topped the list of countries seeking to pilfer secrets from U.S. firms, costing American businesses billions of dollars every year.

“Again, we urge the U.S. side to drop its wrongful fabrication of stories and deliberate mudslinging toward China, as well as stop its large-scale, systematic cyber attacks on other countries,” said the Chinese spokesman.

The U.S. side’s attempt to divert attention by accusing others will not succeed, Hong added.