Chinese President Xi Jinping has told his US counterpart Joe Biden that the Taiwan question is the "first red line" that must not be crossed by Washington, and warned that Beijing will not "sit on its hands" if "Taiwan independence" forces step up their "separatist activities" with the help of external elements.

Biden spoke on the phone with Xi on Tuesday, marking the first conversation between the two leaders since their historic in-person summit last November in San Francisco and the latest in ongoing efforts by US and Chinese officials to defuse tensions between the two countries.

The White House described the one-hour-45-minute conversation as “candid and constructive” on a range of issues on which the leaders agreed and disagreed. Biden stressed the need to maintain “peace and stability” across the Taiwan Strait and he also raised his concerns over China’s support for Russia’s defence industry, the White House said. China’s Foreign Ministry also said the two leaders had a “candid and in-depth exchange.” In the call, Xi characterised the US-China relations as “beginning to stabilise,” but he warned that “negative factors” had been growing and required “attention from both sides,” a ministry readout said.

However, the Chinese statement on Taiwan stood out.

On Taiwan, a key point of friction between the two countries, Xi called the issue the “first red line” in the relationship and urged the US to act in accordance “with President Biden’s commitment of not supporting ‘Taiwan independence,’” the readout said.

China’s ruling Communist Party claims the self-ruling democracy as its territory and has vowed to “reunify” with it, by force if necessary.

"In the face of “Taiwan independence” separatist activities and external encouragement and support for them, China is not going to sit on its hands, Chinese Foreign Ministry Spokesperson Wang Wenbin quoted President Xi as telling Biden.

Xi urged the US side to translate President Biden’s commitment of not supporting “Taiwan independence” into concrete actions.

Next month, Taiwan will inaugurate its president-elect, William Lai Ching-te, whom Beijing has called a "troublemaker" and "separatist." The two presidents also discussed trade and technology issues during their telephone talks.The US side has adopted a string of measures to suppress China’s trade and technology development and is adding more and more Chinese entities to its sanctions lists. This is not “de-risking,” but creating risks.

"If the US side is willing to seek mutually beneficial cooperation and share in China’s development dividends, it will always find China’s door open; but if it is adamant on containing China’s hi-tech development and depriving China of its legitimate right to development, China is not going to sit back and watch," Wang quoted Xi as saying.

Biden and Xi last spoke on the phone in July 2022.

Xi stressed that the issue of strategic perception is always fundamental to the China-US relationship, just like the first button of a shirt that must be put right.

"Two big countries like China and the United States should not cut off their ties or turn their back on each other, still less slide into conflict or confrontation. The two countries should respect each other, coexist in peace and pursue win-win cooperation. "The relationship should continue moving forward in a stable, sound and sustainable way, rather than going backwards," Xi was quoted as saying.

In a significant mark of the Biden administration’s ongoing engagement with Beijing, Treasury Secretary Janet Yellen is scheduled to visit China later this week, where she will meet with her Chinese counterparts on her second visit to the country as Treasury Secretary.

In January, National Security Advisor Jake Sullivan met with the Chinese foreign minister Wang Yi in Bangkok, and Secretary of State Antony Blinken met with Wang Chinese official in Munich in February.

Blinken is also set to travel to China “in the coming weeks,” the senior administration official told reporters on Monday in Washington while Defence Secretary Lloyd Austin is expected to participate in a call with China’s minister of defence “soon.”

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