BEIJING (REUTERS) - China's Foreign Ministry on Saturday (March 17) expressed its "resolute opposition" after United States President Donald Trump signed legislation that encourages the US to send senior officials to Taiwan to meet Taiwanese counterparts and vice versa.

China urges the US to handle Taiwan-related issues caustiously to avoid causing serious harm to Sino-US ties and peace and stability in the Taiwan Strait region, the ministry said in a statement.

China considers self-ruled and democratic Taiwan to be a wayward province ineligible for state-to-state relations.

The Bill, which is non-binding, 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, as Trump has enacted tariffs and called for China to reduce its huge trade imbalance with the US, even while Washington has leaned on Beijing to help resolve tensions with North Korea.

On Friday, Chinese Foreign Ministry spokesman Lu Kang reiterated that Beijing was opposed to the legislation and urged the United States to abide by the "one China" policy and cease official exchanges with Taiwan.

In a statement after Trump's signing of the Bill, the Chinese embassy said clauses of the legislation "severely violate the one-China principle, the political foundation of the China-US relationship."

"China is strongly dissatisfied with that and firmly opposes it," the statement said, adding that the United States should "stop pursuing any official ties with Taiwan or improving its current relations with Taiwan in any substantive way."

The US does not have formal ties with Taiwan but is required by law to help it with self-defence and is the island's primary source of weapons.