Chinese media on Friday dismissed Washington's call to lift Internet censorship, but in a sign of the case's sensitivity the critical Chinese reports were then cut from websites.
Beijing had earlier sought to shift focus away from the spat over Internet curbs and U.S. Internet giant Google's threats to quit China, urging the Obama administration to deal with more pressing issues such as trade, Taiwan and Tibet.
The Chinese government had no immediate response to U.S. Secretary of State Hillary Clinton's speech on Thursday calling for China and other authoritarian governments to lift their restrictions on citizens' use of the Internet.
Some sections of the Chinese media, however, were quick to criticize Clinton's remarks, without citing any official comment. The outspoken Global Times condemned Washington for preaching to other nations.
In a sign the issue has struck a raw nerve, most of the Chinese responses were themselves cut from websites within hours of appearing.
It was unclear why they were removed, but Chinese websites often adjust or cut content based on propaganda authority instructions, especially for sensitive issues.
Clinton's speech criticized the cyber policies of China and Iran, among others, and demanded Beijing investigate complaints by Google Inc, the world's biggest search engine operator, about hacking and censorship.
A new information curtain is descending across much of the world, said Clinton, calling growing Internet curbs the present-day equivalent of the Berlin Wall that contravene international commitments to free expression.
U.S. Assistant Secretary of State Kurt Campbell told reporters Washington had discussed the Google case with China several times from working levels to very senior levels.
It was unclear how the United States could prod China into opening up the Internet. Some fear strong-arm tactics could backfire and make China control content even more tightly.
The Internet has joined trade imbalances, currency values, U.S. weapons sales to Taiwan, and tensions over human rights and Tibet among the quarrels straining ties between the world's biggest and third biggest economies.
CHINESE MEDIA ROUND ON CLINTON
Chinese newspapers took a swipe at Clinton for meddling in other nations' affairs.
The United States' so-called Internet freedom is freedom under U.S. control, the Global Times said.
There's some wishful thinking in the United States making Internet freedom a state policy to be preached to other countries, the tabloid quoted one Chinese scholar as saying.
Facebook, Twitter and YouTube are blocked in China, which uses a filtering firewall to prevent Internet users from seeing overseas web sites with content anathema to the Communist Party.
On Thursday, however, Chinese Vice Foreign Minister He Yafei played down the dispute with Google, and laid out other worries that could deepen strains with Washington.
This year, China and the United States -- especially the U.S. -- must both carefully handle the issues of weapons sales to Taiwan, the Dalai Lama, and trade frictions, He said in comments reported by the official China News Service late on Thursday.
If these few issues are poorly handled, there may be conflict and rifts in bilateral relations, said He in remarks made before Clinton spoke.
This month, China denounced the U.S. sale of Patriot air defense missiles, capable of intercepting Chinese missiles, to Taiwan, which Beijing claims as its own.
China announced its own anti-missile test soon after.
Beijing has warned that more U.S. weapons sales to Taiwan could badly bruise relations with Washington, and has urged President Barack Obama not to meet the Dalai Lama, the exiled Buddhist leader of Tibet who Beijing denounces as a separatist.
I think over the short haul (the Google issue) is going to go away because other problems that the U.S. and China face are rather numerous, said Niu Jun, an international studies expert at Peking University.
I think economic and trade issues are still more important. Both sides will find a positive solution through talks. But this is not necessarily just a simple commercial issue. I don't know what the solution will be. But it won't take a long time.
Among other issues, Beijing accuses Washington of protectionism in anti-dumping cases against Chinese exports like tires and steel, while Washington says Beijing stokes global economic imbalances and the U.S. trade deficit by undervaluing its currency.
(Additional reporting by Ben Blanchard, Lucy Hornby and Yu Le; Editing by Jeremy Laurence)