Washington (CNN) -- The U.S. top military officer said that, should China's military be found to be behind hacks into the U.S. infrastructure, it would not necessarily be a hostile act.
Gen. Martin Dempsey, the chairman of the Joint Chiefs of Staff, said he "believe(s) someone in China is hacking into our systems and stealing technology and intellectual property, which at this point is a crime."
But Dempsey said in testimony to the Senate Armed Services Committee that he cannot attribute the Chinese hacking to China's military, the People's Liberation Army (PLA).
Asked by Sen. Lindsey Graham, R-South Carolina, that if it could be proven that the PLA was behind a hacking of the defense infrastructure, whether it would it be considered a "hostile act," Dempsey said such wasn't necessarily the case.
"I would consider it a crime," Dempsey said.
Asked what he would consider a hostile act, Dempsey said "attacking our critical infrastructure" would be a act worthy of a similar response.
Graham noted he was about to lunch with the vice president of China, who is in the U.S. this week, and asked Dempsey if there was anything he wanted to pass on to Xi Jinping.
"Happy Valentine's Day," Dempsey replied.