U.S. President Donald Trump on Friday signed legislation that encourages the United States to send senior officials to Taiwan to meet Taiwanese counterparts and vice versa, angering China, which views the self-ruled island as a wayward province.

The bill, which is nonbinding, would have gone into effect on Saturday morning, even if Trump had not signed it, said the White House.

The move adds to strains between the two countries over trade. Trump has enacted tariffs and called for China to reduce its huge trade imbalance with the United States, even while Washington has leaned on Beijing to help resolve tensions with North Korea.