Military ties between the United States and China are showing "significant progress" with both sides engaged in a useful dialogue as well as joint exercises, a top US admiral said Thursday.

Three years since military relations hit a low point with Beijing suspending contacts, senior officers are holding regular talks and gaining a better understanding of each country's concerns, Admiral Samuel Locklear, head of the US Pacific Command, told a news conference.

"And I think that the progress that we're making between our two militaries is quite commendable," Locklear said.

The four-star admiral spoke after having taken part in this week's talks in Washington between the United States and China, an annual meeting that covers security as well as economic issues.

US frustration with Chinese cyber hacking against American companies featured high on the agenda in the discussions but Locklear made no mention of digital spying in his remarks.

The defense dialogue in recent months has underscored common ground while clarifying areas of disagreement, he said, allowing commanders to "manage it (friction) so that diplomacy can continue to work."

"So I think that alone is significant progress," he added.

He also pointed to a recent humanitarian disaster relief exercise in Brunei in which Chinese and US forces "just finished operating side by side" as further evidence of improving relations, as well as a port visit by the USS Shiloh in China.

For the first time, the Chinese navy will be taking part in RIMPAC, a major three-week naval exercise in 2014 led by the US Third Fleet.

He said China's decision to participate is "a big step for the Chinese military."

Locklear acknowledged that China had a different interpretation of maritime law than the United States, with Beijing insisting on sovereign authority over "economic" zones and Washington insisting on freedom of navigation outside of defined territorial waters.

But he expressed optimism that top officers could continue to work out "rules of the road" to avoid incidents or tensions on the high seas, as China extends the global reach of its navy.

"So we have to manage our ability to operate around each other. And I think that's ...a doable thing," he said.

He also said the Pentagon's investments in weapons designed to bolster US air and sea power are not aimed in any way at containing China.

"We're too interconnected in too many ways for us to have a containment policy, a military containment strategy," he said.

The US policy was "one of cooperation and collaboration" with China, he said.

But he added the United States will ensure its interests around the world "are well defended."

China broke off military relations in 2010 after the United States announced a major arms deal with Taiwan, which Beijing claims as part of its territory.