Barack Obama criticised internet censorship as he spoke to students in Shanghai today and praised freedom of expression and political participation.
The US president told the gathering of 400 young people that his country regarded such liberties as universal values. But he stopped short of direct reference to human rights abuses in China, as some activists had urged. Aides have said that Obama, who arrived tonight in the capital, Beijing, last night, will raise them in his meetings with Chinese leaders.
He will hold a joint press conference with President Hu Jintao and visit the Forbidden City on a brief sightseeing break in the bilateral discussions. The two men met for dinner tonight.
Sinologists in the US have long encouraged Washington to reach out to the Chinese public, as well as its leaders. But yesterday's meeting underlined the difficulties of doing so.
The event had been billed as a town hall-style meeting, but Chinese officials rejected US proposals that 1,000 people should attend and that it should be broadcast live nationwide.
Instead, it was streamed on the White House site, broadcast live on a local Shanghai television channel and transmitted in text form on state news agency Xinhua's website. Most Chinese citizens will have seen only brief extracts – not including the remarks on censorship.
Although Obama selected questioners from the audience, those in the hall were picked by officials at Shanghai institutions. At least two of those who spoke were thought to be student officers of the Communist Youth League. Other questions were posted by internet users.
One issues raised concerned arms sales to Taiwan – in a question Obama did not directly answer – another about the president's Nobel Peace Prize.
It was the US ambassador Jon Huntsman who read out the question about China's "Great Firewall" and the blocking of Twitter, posted on a US government site. "I think that the more freely information flows, the stronger the society becomes, because then citizens of countries around the world can hold their own governments accountable," Obama said. "They can begin to think for themselves."
He described himself as "a big supporter of non-censorship" and said criticism made him a better president.
The comments on web censorship were carried on Xinhua, though bloggers reported that they disappeared from another news site.
One Twitter user wrote: "I will not forget this morning; I heard, on my shaky internet connection, a question about our own freedom which only a foreign leader can discuss."
But influential Chinese blogger Michael Anti wrote: "Except for the internet freedom Q&A, Obama was too soft, carefully avoiding confronting China, so it made his town hall fail."
In brief opening remarks Obama repeated earlier assurances that America welcomed China's rise, saying co-operation had made both countries more prosperous and secure. He also said that the US did not seek to impose any system of government on other nations.
But he continued: "These freedoms of expression, and worship, of access to information and political participation - we believe they are universal rights. They should be available to all people, including ethnic and religious minorities, whether they are in the United States, China or any nation."
His predecessors Bill Clinton and George Bush were more explicit in highlighting concerns – while praising Chinese advances – when they spoke to students.
Nicholas Bequelin, Asia researcher at Human Rights Watch, said Obama had framed liberties as a question of political culture rather than international legal norms.
"What's important is to put a degree of pressure on the Chinese government for its repressive practices," he said. "You cannot do that without a degree of straight talk. That's not what happened at this meeting … What was needed was to include things relevant to what is happening in the country –as he did in Cairo, for example."
Campaigners reported that dozens of activists, petitioners and dissidents have been detained ahead of Obama's arrival. Such round-ups are common during major visits.
The US president also suggested the two countries now shared the "burden of leadership".
"There are very few global challenges that can be solved unless the US and China agree," he told a questioner, citing climate change.
"There are very few global challenges that can be solved unless the US and China agree," he told a questioner, citing climate change.
Officials still hope for progress on climate change in the bilateral talks, despite Obama's acknowledgement this weekend that time had run out to secure a legally binding deal at Copenhagen.
Economic and trade issues will also be a high priority, as will North Korea and Iran's nuclear programmes and the future of Afghanistan and Pakistan.