The U.S. made a move this week to strengthen its relationship with Taiwan, raising eyebrows in China, which strongly opposes countries pursuing ties with the island-nation.

The U.S. House Foreign Affairs Committee passed two bills on Tuesday aimed at bolstering “the critical U.S.-Taiwan partnership,” according to a statement. One bill, called the Taiwan Travel Act, encouraged high-level visits between Washington and Taipei “at all levels of government” while the second addressed Taiwan’s exclusion from the World Health Organization.

Currently, the State Department enforces self-imposed restrictions on official travel due to the unofficial nature of the bilateral alliance.

Once Sino-U.S. ties were established in 1979, Washington cut off diplomatic links with Taipei in adherence with Beijing’s “One China” policy, which recognizes the East Asian island as part of China. Since then, no Taiwanese leader has formally visited the White House, but that could change if Tuesday’s bill gets signed into law.

Washington still maintains cultural, commercial and security ties with Taipei.

A state-run Chinese newspaper denounced the bill’s passage, saying it could shake political ties with Chinese President Xi Jinping’s administration.

“The mainland will surely act to make sure Taiwan and the U.S. pay the price for their high-level exchanges,” said a Wednesday op-ed published by The Global Times, a nationalistic arm of the Communist Party media apparatus.

“Beijing’s diplomatic retaliations toward Washington will come from all sides,” it continued. “This will multiply exponentially the costs for the U.S, of handling global affairs and make the country profoundly realize that the Taiwan question is the Chinese mainland’s bottom line that it cannot afford to touch.”

China’s foreign ministry has not yet answered CNBC’s request for comment on the matter.

Since coming into office, President Donald Trump’s actions on Taiwan have caused anxiety in the world’s second-largest economy. Those include a 2016 phone-call with Taiwanese President Tsai Ing-wen, who Beijing believes is pushing for Taiwanese independence, and a 2017 decision to sell Tsai’s government $1.42 billion in arms.