Wang said he returned the letter on Tuesday in his capacity as the president of the UN Security Council, saying he believes the UN Secretariat will soon take the same action.

Chen's first letter to UN Secretary-General Ban Ki-moon, in which he applied for UN membership under the name of Taiwan, was returned by the UN Secretariat on July 20.

Chen Shui-bian's "petty trick" of sending a second letter is an extremely grave separatist move aimed at "Taiwan independence" and has once again exposed himself as a "downright international troublemaker," the ambassador said.

"As is widely known, there is but one China in the world. Taiwan is an inalienable part of the Chinese territory, and the government of the People's Republic of China is the sole legitimate government representing the whole of China," Wang said.

"China's representation naturally covers Taiwan," the ambassador said.

Taiwan, as a part of China, has no qualification whatsoever to join the United Nations under any name or in any way, he stressed.

"This is a stand generally upheld by the international community that fully conforms to the principles of the UN Charter," Wang said.

Chen Shui-bian's repeated attempts to challenge the UN Charter, Resolution 2758 of the UN General Assembly and the one-China principle are extremely unpopular and doomed to failure, the ambassador said.

Wang said China appreciates the United Nations' one-China stance and its maintenance of General Assembly Resolution 2758. He said he believes the government and people of China will continue to have the understanding and support of the UN and its members in China's just cause of safeguarding national sovereignty and territorial integrity.