Cybersecurity is among the top defense priorities of the United States, the U.S. Navy’s top admiral said this week - on the same level as strategic nuclear defense.

Admiral Jonathan Greenert, the Navy's chief of operations, said that spending on cyber defense had continued even against a broader background of spending cuts.

Speaking to Reuters in Singapore before the Reuters Cybersecurity Summit in Washington this week, Greenert said, "The level of investment that we put into cyber in the department is as protected or as focused as it would be in strategic nuclear. It's right up there, in the one-two area, above all other programs."

Last week the Pentagon said for the first time that cyber attacks on the United States were directly attributable to China. “In 2012, numerous computer systems around the world, including those owned by the US government, continued to be targeted for intrusions, some of which appear to be attributable directly to the Chinese government and military,” a Pentagon report said. China vigorously denied the reports, saying that the U.S. was “the real hacking empire.”

Greenert said that the Navy put particular importance on cybersecurity because its ships and planes depend heavily on computer networks.

"We've got to understand how to defend them, how to exploit them ourselves and how to, as necessary, be able to do offensive effects," said Greenert. "Many people who look at the future of warfare say it's bound to start in cyber. The first thing you'd want to do is shut down their sensors, interrupt their power grid, confuse them - and presumably guard against that kind of thing and recognize if it's starting."