US lawmakers voted Wednesday to greenlight an agreement aimed at deepening economic relations with Taiwan that has already provoked an irritated response from Beijing.
The US-Taiwan Initiative on 21st Century Trade streamlines customs checks, looks to improve regulatory procedures and establishes anticorruption measures.
It now heads from the House of Representatives to the Senate, the upper chamber of the US Congress, where it is expected to be ratified, according to AFP.
Washington does not have official diplomatic relations with self-governing Taiwan, which China claims as part of its territory.
The governments maintain unofficial ties, however, through the de facto US embassy on the island, the American Institute in Taiwan, which signed the agreement earlier this month with the Taipei Economic and Cultural Representative Office in the United States.
Washington has remained a key ally and arms supplier to Taiwan despite switching diplomatic recognition from Taipei to Beijing in 1979. It is also the island's second-largest trade partner.
But Beijing balks at any hint of diplomatic relations between Taiwan and other governments because it considers the self-ruled island its own territory.
China warned Washington ahead of the deal being inked by both sides against any pact "with connotations of sovereignty or of an official nature with China's Taiwan region."
In April, Beijing conducted three days of military exercises simulating a blockade of the island in response to US House of Representatives Speaker Kevin McCarthy and Taiwanese leader Tsai Ing-wen meeting in California.