Defense Secretary Chuck Hagel said on Friday that cyber threats posed a "quiet, stealthy, insidious" danger to the United States and other nations, and called for "rules of the road" to guide behavior and avoid conflict on global computer networks.

Hagel said he would address cyber security in his speech on Saturday to the Shangri-La Security Dialogue in Singapore and the issue was likely to come up in a brief meeting with Chinese delegates on the margins of the conference.

"Cyber threats are real, they're terribly dangerous," Hagel told reporters on his plane en route to the gathering. "They're probably as insidious and real a threat (as there is) to the United States, as well as China, by the way, and every nation."

Cyber conflict could lead to "quiet, stealthy, insidious, dangerous outcomes," from taking down power grids to destroying financial systems or neutralizing defense networks, Hagel said.

"That's not a unique threat to the United States, (it affects) everybody, so we've got to find ways here ... working with the Chinese, working with everybody, (to develop) rules of the road, some international understandings, some responsibility that governments have to take," he said.

Hagel's remarks came two days after news reports said the Defense Science Board - a committee of civilian experts who advise the Defense Department - had concluded that Chinese hackers have gained access to the designs of more than two dozen major U.S. weapons systems in recent years. The Pentagon downplayed the report as outdated and overstated.

But the Defense Department underscored its concern about Chinese hacking in a separate report to Congress earlier this month, accusing Beijing of using cyber espionage to modernize its military.

The report said the U.S. government had been the target of hacking that appeared to be "attributable directly to the Chinese government and military."

Asked about Hagel's comments, Chinese Foreign Ministry spokesman Hong Lei said China wanted to exchange views with U.S. officials on "relevant issues" on the sidelines of the Singapore meeting.

"We believe that on this issue both sides should sit down and carry out an even-tempered discussion," Hong told a daily briefing, referring to cyber security.

"We should make the cyber security issue a highlight of bilateral cooperation and make joint efforts to maintain an open, cooperative, secure and transparent cyberspace," he said.

"Threat to all"

President Barack Obama has made cyber security a priority of the administration and will discuss his concerns with Chinese President Xi Jinping in a meeting in California next week, White House spokesman Jay Carney said this week.

Hagel told reporters on his plane to Singapore that he had invited Chinese Defense Minister Chang Wanquan to visit the United States and a trip was being organized for August.

Asked whether it was effective to deal with the issue by publicly naming China, Hagel said he thought both public diplomacy and private engagement were necessary. Public statements are necessary to let people know what is going on, he said, but it doesn't solve problems.

"The United States knows ... where many of these incursions come from," Hagel said. "It's pretty hard to prove that they are directed by any specific entity, but we can tell where they come from. And I think we've got to be honest about that."

The problem will ultimately be solved by more private discussions, he added. "But it has to be public as well and we'll deal with this. We must deal with this. This is a very dangerous threat to all of us."

Hagel is due to spend two days at the Shangri-La dialogue, engaging in bilateral and trilateral meetings with his Asian counterparts. He helped gain support for the annual dialogue as a U.S. senator more than a decade ago and was a leader of the first U.S. congressional delegation to the event.

After Singapore, Hagel will travel to a NATO ministerial meeting in Brussels that will hold its first review of cyber defense, a sign the issue is climbing to the top of the alliance's agenda due to concerns its infrastructure and secrets are vulnerable.

NATO Secretary-General Anders Fogh Rasmussen has said NATO systems face "regular" computer attacks. Of particular concern are the systems used to coordinate military actions among the 28 allied nations.

Hagel said cyber security would be a centerpiece of the NATO defense ministers meeting, adding "we all need to find ways, international standards, agreements" to commit to responsible use of cyber and "deal with these real threats."