Chinese President Jiang Zemin has demanded that Washington apologise for the collision between a US Navy spy plane and a Chinese fighter jet.
Jiang also said the US should bear all responsibilities for the collision.
It is the first time Jiang has publicly called for a US apology.
Previously, Jiang said Washington was fully responsible for the incident involving a US Navy EP-3 reconnaissance plane. The Chinese president has also called for an end to US surveillance flights off China's coast.
The US spy plane made an emergency landing on a Chinese island, and its 24 crew members and the aircraft remain in Chinese custody there.
Speaking before leaving on a visit to Latin America, Jiang said: "The US side should apologise to the Chinese people" for the collision, the Xinhua report said.
"The United States should do something favourable to the smooth development of China-US relations, rather than make remarks that confuse right and wrong, and are harmful to the relations," Jiang said.
Jiang's remarks came after US President George W. Bush warned China that it risks damaging relations unless it quickly releases the plane's 24-member crew.
"It is time for our servicemen and women to return home," Bush said at the White House. "It is time for the Chinese government to return our plane."
Bush said he wanted to give China time to respond to the episode to prevent the stalemate from escalating into a full-fledged crisis. But, the president said, a grace period was quickly running out.