National People's Congress session spokesman Li Zhaoxing speaks to the media during a news conference in the Great Hall of the People in Beijing on Thursday. [Nir Elias / Reuters]

Beijing: Using the Taiwan question to interfere with China's internal affairs is "unacceptable", said Li Zhaoxing, spokesman for the annual session of China's top legislature, on Thursday.

"How come it is so difficult for certain Western politicians to remember the simple fact that there is only one China and Taiwan is part of it?" Li asked at a press conference one day before the opening of the third session of the 11th National People's Congress (NPC).

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"When two brothers are hugging each other, someone gives one of them a dagger. What does this mean?" Li asked.

Bilateral relations between China and the United States have been strained since the US announced a $6.4 billion arms sale package to Taiwan in January, and US President Barack Obama and Secretary of State Hillary Clinton met the Dalai Lama last month.

In March 1959, the Dalai Lama - the top religious and political figure in Tibet before New China was founded - led a failed armed rebellion for the independence of Tibet, which has been an inalienable part of China since the 13th century. The Dalai Lama later fled to India and formed a "Tibet government in exile".

In what analysts described as a trip to "salvage" ties, US Deputy Secretary of State James Steinberg and Jeffrey Bader, a senior official for Asian affairs with the US National Security Council, completed a three-day visit to Beijing on Thursday.

There is no need to worry about China's relations with the West, as long as the West does not use Taiwan- and Tibet-related issues to interfere with China's internal affairs, Li said.

"We cannot understand why certain Western leaders, who have a very tight schedule and many internal affairs to deal with, could still spare time to meet the Dalai Lama who they say is a religious figure but is actually in political exile," Li said.

"Why did the Dalai Lama propose a 'Greater Tibet' and keep the 'government-in-exile' with a so-called constitution while claiming he is not in support of 'Tibet independence'?" he asked.

"A very close friend ... who served in an important post in the US government, said the Dalai Lama was a 'political monk'," Li said.

Citing a poem by the sixth Dalai Lama, Li said: "Lies always look flamboyant and smell fragrant, so we must be cautious."