Groundless accusations and "microphone diplomacy" are not solving any problems, said spokesman of the Chinese embassy in Washington Zhu Haiquan on Monday.
Zhu was responding to a NBC report which accused China of trying to invade senior U.S. government officials' private email.
"Combating cross-border network hacker attacks needs strengthening cooperation of the international community," he said.
NBC said in the report that "Chinese hackers have been reading the private emails of Obama-administration officials" and "top national security and trade officials" since 2010.
However, the Guardian quoted U.S. technology consultant Lauren Weinstein as saying that he was skeptical about the anonymous attribution to China for the attack.
"Just about every email address ever published on a web page is subjected to phishing attacks sooner or later these days, " Weinstein said, "If you phish at a few hundred million email addresses, you'll probably suck up a bunch of them from government officials in the process, whether you specifically targeted them or not. "
Chinese cybersecurity expert Qin An said the U.S. and China are preparing Chinese President Xi Jinping's state visit in September.
At this crucial moment, he added, that the U.S. media frequently trumpet about the network security issue seems to attract attention, and the issue may become a major topic during the leaders' meeting.