China's National People's Congress (NPC) expressed strong indignation at and firm opposition to the United States on its signing into law of the Reciprocal Access to Tibet Act of 2018, said a statement issued by the NPC Foreign Affairs Committee Thursday night.

The act, which smears the opening-up policy of China's Tibet and fanfares to take a discriminatory visa policy towards related Chinese officials in the so-called "reciprocal principle," is against the basic norms of international relations and gross interference in China's domestic affairs, said the statement.

The U.S. side should also take effective measures to eliminate adverse effects brought by the act and not to implement the act to avoid severely impairing China-U.S. relations and bilateral cooperation in key areas, the statement said.

China's foreign ministry on Thursday said it resolutely opposes a new U.S. law on Tibet which sends "seriously wrong signals" to Tibet separatists and will do harm to China-U.S. exchanges and cooperation if implemented. 

"Tibet is an internal affair and that Beijing allows no foreign interference," said Hua Chunying, a spokesperson for the ministry, at a regular press conference warning that the law seriously violates basic norms of international relations. 

Hua noted that China's Tibet Autonomous Region will become more and more open and China welcomes people from abroad to visit and do business in Tibet under the prerequisite to abide by Chinese laws and relevant regulations and go through necessary procedures.

U.S. President Donald Trump on Wednesday signed into law the Reciprocal Access To Tibet Act of 2018. 

The law promotes access to Tibet for U.S. diplomats, journalists, and tourists by denying entry into the U.S. for Chinese officials deemed responsible for restricting access to Tibet.

(With inputs from Xinhua News Agency)