China has warned the US that it would take "forceful measures" to resolutely safeguard its own interests after President Donald Trump signed a new law that imposes a visa ban on Chinese officials denying American citizens access to Tibet. Trump signed the Reciprocal Access to Tibet Act of 2018 into law Wednesday which passed by US Congress and the Senate, enraging China. China insists Tibet has been part of its territory for centuries. The Dalai Lama fled to India in 1959 amid an abortive uprising against the Chinese rule in his Himalayan homeland. Foreigners have to seek special permission from China to visit Tibet. US citizens, including government officials, reporters and tourists who seek to enter Tibetan areas are routinely rejected, and the few who do get in are forced to stay on strictly controlled official tours, where the true situation of the Tibetan people is hidden from them, American officials say. While the Chinese foreign ministry warned of consequences, China's National People's Congress (NPC) on Thursday night expressed strong indignation and firm opposition to the United States for enacting the law. Also read:\u00a0China accuses US of \u2018fabricating facts\u2019 with hacking charges The act is against the basic norms of international relations and a gross interference in China's domestic affairs, a statement issued by the NPC Foreign Affairs Committee said. It has sent a seriously wrong message to "Tibetan independence" forces, the statement said. Stressing that Tibet affairs are purely China's domestic affairs and allow no interference from other countries, the statement said adding that Tibet and Tibetan areas in the other four provinces are open to people from around the world. Since 2015, the number of visitors to Tibet and these regions from the United States alone has reached nearly 40,000, including multiple delegations of US Congressmen received by the NPC, it said. It defended the restriction of entry of foreigners, saying that taking into consideration factors such as Tibet's special geographic and climatic conditions. The Chinese government has taken certain administrative measures in accordance with laws and regulations for foreigners to enter Tibet, which are totally necessary and give no ground for blame. The act's accusations against China disregard the facts and are full of prejudice, and completely unacceptable by the Chinese side, it said. "If the US side implement the act, it will definitely cause serious damage to bilateral relations including exchanges between legislative bodies of both countries, and China will take forceful measures to resolutely safeguard its own interests," the statement said. The Chinese Foreign Ministry spokesperson Hua Chunying on Thursday said China welcomes more and more foreigners to Tibet for visit, travel and business, and this policy will remain unchanged. But the precondition is that they must abide by the Chinese laws and relevant regulations and go through necessary procedures, she said. \u201cWe urge the US side to fully realise the highly sensitive nature of Tibet-related issues, stop using them to interfere in China's internal affairs and refrain from putting the act into effect, otherwise the US itself has to bear all the consequences that may cause," she said. This is the second major move by US relating to Tibet this month. Earlier this month a US official said Chinese government must not decide religious matters such as choosing the Dalai Lama amid fears that China will appoint a successor to the Tibetan spiritual leader aligned to its interests. Meanwhile, officials in Tibet stepped up criticism against the Dalai Lama. Tibet regional authorities have published a series of articles urging the public to completely understand the 14th Dalai Lama's "reactionary essence in politics," "hypocrisy in religion" and fraudulence in his tricks, state-run Global Times reported on Friday.