SINGAPORE (AP) — Defense Secretary Chuck Hagel is warning an international security conference that the U.S. “will not look the other way” when nations such as China try to restrict navigation or ignore international rules and standards.

Hagel says China’s territorial claims in the South China Sea are destabilizing the region, and its failure to resolve disputes with other nations threatens East Asia’s long-term progress.

The Pentagon chief also is calling out China for cyberspying against the U.S., a longstanding complaint that has become more formal. About two weeks ago U.S. prosecutors charged five Chinese military officers with hacking into American companies to steal trade secrets.

Hagel is speaking at the Shangri-La Dialogue, where he is reassuring Asia Pacific nations that the U.S. is committed to the region.