Eighty percent of Chinese government websites have been attacked by hackers, with most of the assaults launched from the United States, a top Chinese Internet regulator said on Thursday.

Lu Wei, head of the State Internet Information Office, condemned the use of "superior technology to attack or steal secrets." But he described U.S.-China dialogue on cybersecurity as "unhindered," less than a week after the talks appeared to have stalled.

Chinese state councilor Yang Jiechi told U.S. Secretary of State John Kerry this month that resuming cybersecurity cooperation between China and the United State would be difficult because of "mistaken U.S. practices."

Speaking to reporters at a Beijing news conference on Thursday to publicize an Internet conference, Lu said the two countries had "differences but also commonalities," and he hoped they could find common ground.

Cooperation between Washington and Beijing on fighting cyber crime ground to halt earlier this year after the U.S. Justice Department charged five Chinese military personnel with hacking U.S. companies to steal trade secrets.

Chinese officials have stepped up their counter-accusations of U.S. government hacking since former National Security Agency contractor Edward Snowden claimed the United States had broken into networks and servers in China and Hong Kong.

Lu also defended China's ban on foreign Internet services such as Facebook Inc., saying they were meant to protect the national interest.

"I've never shut down a website outside of China," Lu said. "China has always been very hospitable, but we can choose who enters our house."

Lu disputed news reports in September that quoted him as saying Facebook would "never" be allowed to enter China. "I didn't say Facebook could not enter China, but nor did I say that it could," he said.