U.S. President Barack Obama faces tensions with China over trade and Tibet on his first visit to the emerging superpower for a summit that will grapple with economic imbalances and the future of the yuan.

Obama arrived in Shanghai, east China's commercial hub, late on Sunday in heavy rain and is due to meet city officials and hold a town hall-style meeting with young people before heading to Beijing later on Monday.

Chinese state-run Internet sites have asked the public for suggested questions to quiz Obama at the youth meeting, and many urged him to explain any plans to meet the Dalai Lama, the exiled Tibetan leader whom Beijing brands a separatist.

These events will be a warm-up for Obama's summit with President Hu Jintao in the national capital on Tuesday that will cover trouble-spots such as North Korea and Iran, and efforts to forge a new climate pact.

Obama has said he will also raise the sensitive subjects of human rights, and sometimes tense trade ties and China's yuan currency, seen by U.S. industry as significantly undervalued and stoking unsustainable global economic imbalances.

"The president will be talking about balanced, strong sustainable growth and the policies that go into making that happen," a U.S. official, speaking on condition of anonymity, told Reuters.

At a gathering of Asia-Pacific leaders in Singapore over the weekend, Hu pointedly ignored international calls for his government to help ease those imbalances by raising the value of the yuan, making Chinese exports relatively more expensive.

He and other senior Chinese officials have instead accused other countries - implicitly including the United States - of embracing damaging trade protectionism aimed at Chinese goods.

But having already made their gripes clear before the summit, Obama and Hu may avoid sharp public jabs as they focus on building goodwill between the the world's biggest and third biggest economies.

China has had a huge trade surplus with the United States, and is also the largest foreign holder of U.S. government
bonds.

The two nations were now like "conjoined twins," said a commentary in the overseas edition of the People's Daily, the official mouthpiece of China's ruling Communist Party.

"Even if one wants to sever itself from the other, that can't be done without injuring oneself," said the commentary, which also said the United States was in no position to criticise China on economic frictions.

"When it comes to the current China-U.S. trade disputes, the United States has been the instigator of irresponsibility."

The commentary took another swipe: "In an interview before his visit, Obama said that he hopes China becomes a "responsible" power. In fact, there would be nothing more fitting than directing these words at the United States."

Obama's meetings with China's leaders were unlikely to yield any big policy shifts on the diplomatic and economic problems facing the two big powers, said Drew Thompson, an expert on China at the Nixon Center in Washington, D.C.

"This isn't a trip about deliverables," Thompson told reporters in Beijing. "It's a trip about staying the course, keeping the two ships on the same course and not letting them bump into one another."

WINNING OVER A WARY CHINA

Obama has cast his visit as an effort to win trust from a government and a public often wary of U.S. intentions towards the rising Asian superpower.

The United States welcomed Beijing's growing global role and "does not seek to contain" it, Obama said in a tone-setting speech on Asian policy in Tokyo on Saturday.

But nearly 80 percent of Chinese respondents who answered an online survey said the United States did not want to see their country rise, a Chinese magazine, Globe, reported last week.

Ben Rhodes, a White House communications official, told reporters with Obama that the Shanghai meeting would be streamed over the White House website (www.WhiteHouse.gov).

It appeared China would not fulfil U.S. hopes for the session to be broadcast nationwide on Chinese television.

Officials wanted to show it only on a local Shanghai service, said Richard Buangan, a spokesman for the U.S. Embassy in Beijing.