BEIJING -- China's National People's Congress has expressed firm opposition to and strong condemnation of the passage and signing into law of the so-called "Promoting a Resolution to the Tibet-China Dispute Act" by the United States, said a statement issued by the NPC Foreign Affairs Committee Saturday.

The act grossly interferes in China's internal affairs and severely undermines China's interests, sending a seriously wrong signal to the separatist forces seeking "Tibet independence," the statement said.

Xizang has been an integral part of the sacred territory of China since ancient times, and Xizang affairs are purely China's internal affairs, which brook no external interference, it stated.

Under the leadership of the Communist Party of China and with the support of the people of the whole country, the people of all ethnic groups in Xizang have worked together and achieved a full victory in poverty alleviation, resulting in greater social stability, economic and cultural prosperity, a better eco-environment, and a happier life for the people, the statement said.

Currently, Xizang's stable development is at its best in history, and the people's freedom of religious belief is fully protected, the statement said, adding that the region continuously breaks new ground in long-term stability and high-quality development.

"Anyone or any forces attempting to obstruct people in Xizang from pursuing a happier and better life will end in vain, and their attempt to contain and suppress China through messing up Xizang is doomed to failure," it said.

The top legislature urges the United States to honor its commitment to acknowledging that Xizang is part of China and not supporting "Tibet independence."

"If the US side insists on manipulating the relevant act, China will take resolute measures in accordance with the law to firmly safeguard its sovereignty, security and development interests," the statement said.