BEIJING, April 29-- China urged the U.S. and Japannot to drag the Diaoyu Islandsinto a bilateral security treaty on Wednesday.

Chinese Foreign Ministry spokesperson Hong Lei was responding to a question on U.S. President Barack Obama's remarks at a joint press conference that the Diaoyu Islands were contained in a U.S.-Japan security treaty. The press conference was held after Obama's talks at the White Housewith Japanese Prime Minister Shinzo Abeon Tuesday.

"No matter what others say or do, the fact that the Diaoyu Islands belong to China can not be changed, " Hong said. He reaffirmed that the Diaoyu Islands are China's inherent territory.

The Chinese government and people will firmly uphold their national sovereignty and territorial integrity, Hong said.

Hong urged the U.S. to take a responsible attitude and keep its promise of a neutral position on the territorial sovereignty issue. He said the U.S. should act in a prudent manner to play a constructive role on peace and stability in the region.

The U.S.and Japan are not the parties concerned in the South China Seadisputes and should keep a neutral position on the issue.

Hong said China's construction on the islands and reefs of Nansha is within China's sovereignty as well as lawful and justified.

When asked to comment on the new guidelines for defense cooperation between the U.S. and Japan, Hong said the U.S.-Japan alliance, a bilateral arrangement forged during the Cold War, should not undermine the interests of third parties or the peace and stability of the Asia-Pacific region.