Standing beside Obama after their summit, Chinese President Hu Jintao avoided mentioning the yuan or the dollar.

Instead, Hu emphasized during a joint media appearance the need to avoid trade protectionism in a thinly veiled reference to China's irritation over new U.S. tariffs on Chinese-made tyres, steel pipes and other products.

With the U.S. unemployment rate at 10.2 percent, one of Obama's priorities during his four-day trip to China is pressing Beijing over the huge trade imbalance between the two countries, a move he believes would pave the way for greater U.S. exports.

Washington says an undervalued yuan disadvantages U.S. manufacturers and is stoking global economic imbalances.

Obama said movement by China on its exchange rate would “make an essential contribution to the global rebalancing effort.”

But his reference to China's “past statements” suggested that Hu might not have been forthcoming on how Beijing might respond.

Hu said the two leaders talked of the need to keep in close contact on macroeconomic and financial policies. “I stressed that under the current circumstances, we need to oppose all kinds of trade protectionism even more strongly,” Hu said.

The United States and China — the world's biggest and third biggest economies — have agreed sustainable global economic recovery requires broad rebalancing, but that could be contentious, especially if it involves China loosening currency controls.

Sun Zhe, director of the Center for U.S.-China Relations at Tsinghua University in Beijing, said Hu's silence on the currency may stem in part from reluctance by China to be seen as making concessions under foreign pressure.

“I personally think that there may be some slight, symbolic adjustment on exchange rate policy after Obama leaves,” said Sun.

“But don't expect much. China believes that the main problem is not the weakness of the yuan but the weakness of the dollar. The feeling here is 'Why should we be the scapegoat for your dollar problems'?”

The issue of currencies has drawn testy comments in recent days from U.S. and Chinese officials. China's Commerce Ministry on Monday rebuffed calls for the yuan to appreciate, signalling resistance to change foreign exchange policy.

Outside pressure has been building on Beijing to let the yuan rise after more than a year of it being nearly frozen in place against the dollar, with the latest appeal voiced by the head of the International Monetary Fund on Tuesday.

Tricky Balance

Obama has faced a tricky balance between courting and cajoling China during his visit.

China has had a huge trade surplus with the United States, and is also the largest foreign holder of U.S. government bonds. But the U.S. president has also sought help from Beijing, with its growing diplomatic sway, on security worries.

The two leaders discussed North Korea and Iran, agreeing to cooperate on addressing both those nuclear disputes, and also promised to work together on fighting global warming.

Hu expressed appreciation that Obama, who arrived in China on Sunday night, had welcomed a “strong, prosperous and successful China that plays an even greater role on the world stage.”

Obama said he told China that all minorities should enjoy human rights and urged China to resume talks with representatives of the Dalai Lama, Tibet's exiled spiritual leader.

Obama did not meet the Dalai Lama when he was in Washington in early October. But the Dalai Lama has said they may meet after Obama returns from China, which condemns the Buddhist monk as a separatist for demanding Tibetan self-determination.

Chinese media have avoided the kind of effusive reception Obama has received in Europe, and police shooed away people on Beijing streets waiting to snap pictures of his motorcade.

Asked if he was frustrated that the Chinese did not seem to cede much ground on issues like human rights and currencies, White House spokesman Robert Gibbs said Obama recognizes that there remains “a lot of work to do” to bridge differences.

Obama did not expect “the waters would part and everything would change over the course of our almost two-and-a-half day trip to China,” Gibbs said.