Chinese Foreign Minister Wang Yi, right, chats with a delegate at a welcome ceremony for visiting Thai Prime Minister Prayuth Chan-ocha at the Great Hall of the People in Beijing on Monday. (Andy Wong/AP)

— China said Tuesday that there was no proof that North Korea was behind a cyberattack on Sony Pictures Entertainment, signaling Beijing’s reluctance to side with the United States over the incident, while also rejecting speculation that it had cut off Pyongyang’s Internet access as punishment.

Asked about U.S. requests for help from China to punish North Korea for cyberattacks, Hua Chun­ying, a spokeswoman for China’s Foreign Ministry, said the United States and North Korea needed to communicate directly with each other.

She said Beijing had not seen proof of who was behind the attack on Sony. “We need sufficient evidence before drawing any conclusion,” she said at a news conference.

Obama administration officials had asked Beijing on Thursday to block Pyongyang’s access to Internet routers and servers in China, to expel North Korean hackers living in China and to pressure the regime of Kim Jong Un to end its alleged cyber-
offensive against U.S. companies, according to one official.

On Monday, North Korea’s Internet went dark for more than nine hours, but who pulled the plug remains a mystery. The U.S. government issued a coy non-
denial that it might have been responsible, and China rejected media speculation that it might have been to blame.

“This kind of reporting has no factual basis. It is speculative and pure assumption. It is not trustworthy at all,” Hua said. “And the reporting itself is irresponsible, nonprofessional and misleading.”

The attack on Sony has put Beijing in a difficult position. On one hand, China wants to cooperate with the United States on cybersecurity and cyberterrorism, but on the other, it does not want to alienate its allies in North Korea.

On Tuesday, State Department spokeswoman Marie Harf said the Chinese “certainly have a role to play” in helping combat North Korean hacking.

China said Foreign Minister Wang Yi, in a phone conversation with U.S. Secretary of State John F. Kerry on Sunday, reaffirmed Beijing’s “unwavering position” on the subject. Hua reiterated the message Tuesday.

“China is against all forms of cyberattacks and cyberterrorism, including cyberattacks launched by any country or individual by using facilities beyond its own national borders against a third country,” she said.

Bloomberg Businessweek quoted an anonymous source Monday as saying that China had agreed to start its own investigation into the attack after the Sunday phone call.

Liu Deliang, a professor and cyber-law expert at Beijing Normal University, said he doubted that China would agree to such an investigation, arguing that Beijing was keen first to help set up an international code of conduct and a legal framework to govern the Internet, with an independent third party established to look into cyberattacks.

But other experts said Beijing’s desire to be seen as a responsible power in global Internet governance means that it might be willing to look into the attack on Sony.

“The conclusion that North Korea attacked Sony is based on inference. So is the conclusion that the United States attacked North Korea. The incidents have not been proved yet,” said Shen Yi, an associate professor in the School of International Relations and Public Affairs at Fudan University.

“Tracking down attackers is always the most difficult task, because it’s hard to know if the IP address belongs to a springboard or is the original source,” he said. “But if China wants to act like a responsible big power, of course it should cooperate with the U.S. to track down the attacker rather than acting passively.”

Trust on cyberspace issues remains low between China and the United States. This year, the United States indicted five People’s Liberation Army computer experts on charges of spying on U.S. companies in cyberspace, prompting the Chinese to pull out of bilateral talks on cyber­security.

Complicating matters, there have been suggestions that the Sony attack could have been routed through Chinese servers, just as an attack on South Korea’s banks is thought to have been last year. Although China may not have been directly responsible, some U.S. experts say it is not doing enough to prevent such attacks.

But Yuan Shengang, chief executive of the private cybersecurity company NetentSec in Beijing, said communication between the United States and China on cybersecurity had improved recently.

Lu Wei, China’s top official in charge of the Internet, was in the United States this month meeting officials in Washington and visiting prominent technology companies on the West Coast.

There is a growing sense in China that cooperation between major powers is necessary to combat cyberterrorism, Yuan said.

“For example, North Korea needs to go through China to access the American Internet,” he said. “China can certainly help with the investigation into the cyberattack, by negotiation, communication, discussion, even by bargaining.”

But Yuan said it was “impossible” to imagine that China had helped North Korea carry out the attack on Sony, especially as relations between the two countries appear to have deteriorated in the past two years and there being no “domestic political atmosphere” for such action.

The cyberattack was apparently retaliation for Sony’s planned Christmas Day release of “The Interview,” a comedy starring Seth Rogen and James Franco about a plot to assassinate the North Korean leader. Sony initially canceled the scheduled theatrical release of the movie, but it backtracked Tuesday and announced a limited release.

Liu Liu and Xu Jing in Beijing and Karen DeYoung in Washington contributed to this report.