A meeting between US and Chinese defence chiefs in Hanoi on Monday offers Washington a chance to improve fragile relations with Beijing's military and make the case for a more "reliable" dialogue, US officials said on Sunday.

The scheduled talks between Defense Secretary Robert Gates and Chinese Defence Minister Liang Guanglie, on the sidelines of an ASEAN conference, are the first between the countries' top military officials in a year and mark the latest attempt by the United States to forge a security dialogue with Beijing.

China has repeatedly broken off ties with the American military due to unhappiness with US policies, including arms sales to Taiwan, much to the frustration of US officials who argue a more regular dialogue would reduce tensions.

US officials played down expectations for the meeting, saying it was merely one step in a broader, delicate effort that would take time to pay off.

"We view this as a long-term process," Pentagon press secretary Geoff Morrell told reporters travelling with the defence secretary.

Gates has called on the Chinese to embrace defence exchanges to avoid misunderstandings and "miscalculations," citing the example of the Cold War-era US dialogue with the Soviet military.

Morrell said it was not a matter of Washington pleading with China to pursue military relations but of persuading Beijing that such a step was in its interests and those of the wider region.

"It's about convincing the Chinese that this is of value to them as it is to us," he said.

President Barack Obama's administration faces a difficult challenge as it tries to build trust with China while also defending the US naval presence in the Pacific and reassuring anxious partners in the region who feel threatened by Beijing's more assertive stance.

China has sharply criticized the United States for recent joint military exercises with South Korea in the Yellow Sea, and for sailing naval ships in the South China Sea.

But the US Navy rejects China's claim to territorial rights in those areas and says it will continue to operate in what it considers international waters.

US officials and lawmakers are anxious about China's growing military power, including its investments in submarines and anti-ship missiles that could potentially undercut the role of American aircraft carriers.

A recent Pentagon report to Congress said China appeared to be expanding its strategic goals and planning to extend its navy's reach further into the Pacific.

Underscoring Washington's diplomatic balancing act, Gates is also due to meet Vietnamese leaders during his visit to the capital, as the country has sought US support in territorial disputes with China.

Given the prospects of an intensifying rivalry with China on the high seas, US officials say more military dialogue is crucial to defusing potential crises.

"We hope that we can work with the Chinese to put in place a framework for this military security relationship that will be able to endure friction and turbulence that is inevitable when you have a relationship of the complexity and scope of the US-China bilateral relationship," said a senior defense official, who spoke on condition of anonymity.

But he added: "We don't think we're there yet."

The on-again-off-again nature of the relationship had left a cloud of uncertainty over the dialogue, the US official said.

"It's not as simple as hitting the off switch and then coming back nine months later and hitting the on switch and proceeding as if everything is, you know, perfectly fine and good."

Even after China severed military ties in January before restoring relations last month, a telephone "hotline" for the two countries had remained in place, Morrell said.

During his three-day visit for the ASEAN security conference, Gates was also due to meet his defence counterparts from Japan, Australia and the Philippines, officials said.