US Defence Secretary Robert Gates has signalled his concern over China's rapid military modernisation.
His move is highlighted by the latest picture of a Chinese stealth bomber
, as he begins talks aimed at repairing security relations in Beijing today.
But Dr Gates warned China not to underestimate the US or the continuing power of its military.
"I've watched this sort of cyclical view of American decline come around two or three times, perhaps most dramatically in the latter half of the 1970s," Dr Gates told reporters en route to China.
"And my general line for those both at home and around the world who think the US is in decline is that history's dustbins are filled with countries that underestimated the resilience of the United States."
This week's discussions, which will include President Hu Jintao, signal an end to an 11-month hiatus in military-to-military relations between China and the US after the $US6.5 billion US sale of arms to Taiwan last February. They come amid mounting evidence Beijing's arms spending spree is paying dividends.
As well as the stealth plane, Washington is worried about China's plans for a groundbreaking anti-aircraft-carrier missile as well as longer-term plans for its own aircraft carriers.
"We've been watching these developments all along," Dr Gates said. "I've been concerned about the development of the anti-ship cruise and ballistic missiles ever since I took this job.
"We knew they were working on a stealth aircraft. I think what we've seen is they may be somewhat further ahead in the development of that aircraft than our intelligence had earlier predicted.
"They have the potential to put some of our capabilities at risk."
Still, he questioned "just how stealthy" the aircraft would be.
China believes the US is not ready to accept another strong military power, especially in the Asia-Pacific. The leaking of the stealth fighter photos has been seen as intentional.
"Whether the reported new weapons are true or not, in the long run China will own first-class weapons that are capable of competing with the US war machine," Communist Party-run nationalist tabloid Global Times said in an editorial last week
"Apparently the US is not ready to treat China as a major power. They cannot accept the fact that China will . . . possess a first-class military. They are too used to the old power structure."
In both countries, civilian governments have to battle with their military machines. Chinese generals regularly emerge in the media advocating more aggressive policies. Dr Gates has reached a compromise to cut $US78 billion ($78.5bn) from his defence budget -- the biggest cut in decades -- as the Obama administration searches for ways to reduce its massive deficit.
Mr Hu will visit Washington next week.