"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."
SOLVED IN PRIVATE
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."
Sign up for MIS Asia eNewsletters.