A senior official of China’s ruling Communist Party has pledged deeper friendship with Taiwan just a day after state media warned that Beijing could wage a war on the self-ruled island if the US enacts a bill urging closer ties with Taipei.

Addressing the opening session of an advisory body to the Chinese legislature on Saturday, the Communist Party’s fourth most senior official, Yu Zhengsheng, softened the tone on Taiwan.

Angered by the American bill, Beijing told Taiwan, which it considers subject to China’s sovereignty, that it would only get burnt if it sought to rely on foreigners, without mentioning the US legislation.

“We will deepen solidarity and friendship with our compatriots in Hong Kong, Macau, and Taiwan as well as overseas Chinese,” Yu stated before a crowd of 2,000 delegates to the Chinese People’s Political Consultative Conference in Beijing.

He further emphasized that the body will “mobilize all the sons and daughters of the Chinese nation to work together for the greater national interests and realization of the Chinese Dream,” referring to Chinese President Xi Jinping's aspiration to restore a rejuvenated China to its full standing globally.

The proposed US bill, which only needs President Donald Trump’s signature to become law, states that the US policy should allow officials at all levels to visit Taiwan and meet their Taiwanese counterparts, permit high-level Taiwanese officials to enter the US “under respectful conditions” and meet with American officials.

Taipei, however, has welcomed the proposed legislation in Washington, with which it has no formal ties.

Trump has affirmed the US’s continued adherence to the “One China” policy, but the new US bill threatens to stir political tensions over the issue once again.

China’s tensions with Taiwan have intensified since the election into office of President Tsai Ing-wen from the pro-independence Democratic Progressive Party in 2016.

China suspects Tsai intends to press for formal independence of the island, which would cross a red line for Chinese leaders.

Beijing regards Taiwan as an integral part of “one China” and ineligible for formal state-to-state ties.