A senior Chinese general has assured US Defense Secretary of Beijing's "no first use" of nuclear weapons policy, reports say. US officials said Gen Jing Zhiyuan made the remarks when Donald Rumsfeld paid an unprecedented visit to the headquarters of China's nuclear arsenal.
Meanwhile Chinese President Hu Jintao urged better military ties with the US.
In a meeting with Mr Rumsfeld, Mr Hu said although the military relationship had improved in recent years there was still room to expand, US defence officials said.
"All this will better help military forces of our two countries to better enhance mutual understanding and friendship," he said.
They discussed US President George W. Bush's visit to Beijing in November and plans to increase military educational exchanges.
Mr Rumsfeld has used the visit to highlight what he describes as a lack of transparency in China's military spending, reports BBC.
The Chinese rejected a Rumsfeld request to visit their national military command center in the Western Hills.
Jing disavowed a recent public suggestion by another Chinese general that the United States could be targeted for a nuclear strike if it intervened in a conflict over Taiwan.
Rumsfeld aides who were present during the discussions quoted Jing as saying it was "completely groundless" to say China was targeting any country with its strategic nuclear forces.
Jing's operations chief, Senior Col. Kang Hong Gui, gave Rumsfeld a briefing, complete with Microsoft PowerPoint graphics, on the command's structure and missile forces training, without details about the numbers of Chinese missiles, some of which could strike points inside the United States.
Later, in a meeting with Rumsfeld at the Great Hall of the People, President Hu Jintao said the visit to the Second Artillery headquarters and Rumsfeld's other discussions in Beijing will "help the military forces of our two countries to better enhance their mutual understanding and friendship," informs the AP.