WASHINGTON—Asserting that cyberattacks against the U.S. don't come only from China, the U.S. and Chinese defense ministers said they agreed Monday to work together on cyber issues to avoid miscalculations that could lead to future crises.

Defense Secretary Leon Panetta said that since China and the United States have advanced cyber capabilities, it is important to develop better cooperation.

"It's true, as the general pointed out, that obviously there are other countries, actors, others involved in some of the attacks that both of our countries receive," Mr. Panetta told reporters after an afternoon meeting in the Pentagon