WASHINGTON • United States President Donald Trump's administration has denied any change to its "One China" policy after Taiwan President Tsai Ing-wen made a political speech in the US, the first time in 15 years a Taiwanese leader has done so.

Beijing said that it had lodged an official protest with the United States over Ms Tsai's speech on Monday in Los Angeles, where she said Taiwan's freedom and future were not negotiable.

Ms Tsai spoke at the Ronald Reagan Presidential Library while in transit on a trip to Paraguay and Belize, two of the few countries that continue to recognise the government in Taipei.

US State Department spokesman Heather Nauert said the speech did not represent any move by the Trump administration to alter the official US stance that accepts Beijing as the sole government of China, and does not officially recognise Taiwan's government.

"Our policy on Taiwan has not changed," she told reporters on Tuesday. "The United States in regard to this trip facilitates from time to time representatives of the Taiwan authorities to transit in the United States.

"Those are largely undertaken out of consideration for the safety and the comfort of those travellers, and that is in keeping with our 'One China' policy."

Yet previous US administrations have prevented Taiwan leaders from making speeches in the United States that would implicitly elevate their diplomatic status and irk Beijing.

Ms Tsai's transit in Los Angeles was the most high-profile since former Taiwan president Chen Shui-bian's 2003 stopover in New York, where he accepted a human rights award and delivered several public speeches.

Ms Tsai's Los Angeles visit, which included a stop at a branch of the Taiwanese coffee chain 85C Bakery Cafe, has also led to backlash from Chinese web users.

The coffee chain's official Weibo account saw a flood of messages threatening to boycott the chain over the visit.

AGENCE FRANCE-PRESSE