China’s Foreign Ministry has expressed its opposition to the Taiwan Travel Act, a bill signed by United States President Donald Trump on Saturday. The non-binding bill aims to increase travel and visits “at all levels”, including senior government officials and business leaders, between the United States and Taiwan.

“As has been pointed out many times by China, the relevant clauses of the act, though not legally binding, severely violate the one-China principle and the three joint communiques between China and the United States,” spokesperson Lu Kang said, according to Xinhua. The bill sends out wrong signals to “pro-independence” separatist forces in Taiwan, Lu said.

China considers Taiwan an integral part of its mainland and opposes any diplomatic relations as well as political contacts with Taipei by countries which have diplomatic relations with it. Currently, only about 20 countries have diplomatic relations with Taiwan. India does not have diplomatic relations with Taiwan and also adheres to the “One-China Policy”. The United States does not have formal ties with Taiwan but is the sole supplier of arms to the country.

“We urge the US side to correct its mistake, stop pursuing any official ties with Taiwan or improving its current relations with Taiwan in any substantive way, and handle Taiwan-related issues properly and cautiously so as to avoid causing severe damage to China-US relations and cross-Strait peace and stability,” Lu said.

China’s Ministry of National Defense said Taiwan is a part of China and any matters regarding it are “completely internal affairs”. The bill has interfered in China’s internal affairs, the ministry said.

“China demands that the U.S. keep its promises, rectify its wrongs, refrain from implementing relevant clauses of the bill and stop seeking any official contacts, military ties or arms sales with Taiwan, so as to avoid doing serious harm to the China-U.S. relationship, the ties between the two countries’ militaries and the peace and stability across the Taiwan Strait,” the ministry’s spokesperson Wu Qian was quoted as saying.

Taiwan, however, has welcomed the legislation and thanked the United States, its “most important ally” for its steadfast support, according to Reuters.

China’s relations with Taiwan remain strained, with the country’s leadership giving Taiwan President Tsai Ing-wen the cold shoulder since she took power in 2016, because she refuses to recognise the “one China” policy.