LONDON (MarketWatch) -- A U.S.-China détente over the role of the dollar in international monetary system was called into question Friday as China's central bank repeated its assertion that a new global reserve currency is needed.

"To prevent the deficiencies in the main reserve currency, there's a need to create a new currency that's de-linked from the economies of the issuers," the People's Bank of China said in its annual financial stability review, according to a report by Bloomberg News.

In an apparent reference to the dollar, the review said the domination of the international monetary system by one currency was a serious defect, according to Reuters.

The report reiterated an essay written in March by People's Bank governor Zhou Xiaochuan urging the creation of a "super-sovereign" currency that would presumably take the dollar's place as the primary reserve currency. Zhou had called for an expanded role for the International Monetary Fund's special drawing rights.

The central bank's comments come after Chinese officials had previously appeared to de-emphasize concerns about the dollar's reserve role following a visit to China by Treasury Secretary Timothy Geithner earlier this month, observers said.

The dollar extended losses versus major rivals following the reports. See full story.

China's softer tone in the wake of Geithner's visit had appeared to recognize that a weaker dollar would damage the value of China's massive dollar-denominated holdings.

But that doesn't mean the Chinese central bank's long-term concerns have disappeared, said Stephen Gallo, head of market analysis at Schneider Foreign Exchange.

"There may be signs here of tensions mounting between the PBOC's economic concerns over China's holdings of dollars and the Chinese government's diplomatic reasons" for toning down its criticism, Gallo said, in e-mailed comments.

The central bank is "still clearly worried about the longer-term opportunity cost of holding dollars -- in as much as it can cite the dollar's role in the global economy as one of the main reasons for the financial crisis -- while the Chinese government is still more happy to play to the tune of the Bernanke-Geithner camp which sees leaning against the wind in order to protect the U.S. dollar as a necessary evil," Gallo said.

But Simon Derrick, chief currency strategist at Bank of New York Mellon, said remarks by Chinese officials have never been particularly clear on the subject.

Because dollar weakness is self-defeating for China, officials appear to have decided not to try to directly talk the dollar down, Derrick said.

At the same time, they recognize they must "push harder" if they want to see a more diversified reserve system, he said.

China is likely to emphasize that it wants to see changes take place over the long run in an effort to shield the dollar in the short term, he said.

But the push is nonetheless likely to weigh on the greenback and could have a significant impact on currency markets as traders attempt to gauge the potential reduction of the dollar's role and what currencies will take its place, analysts said.

"Mind you, China is our single largest holder of foreign debt at $765 billion and so their desire to not only shift their own reserves away from the dollar but pressure others to do the same is absolutely a concern," said Dan Greenhaus, a strategist at Miller Tabak & Co. in New York, in a research note.

William L. Watts is a reporter for MarketWatch in London.

www.marketwatch.com/story/china-repeats-call-for-new-reserve-currency