Lima, Peru - Chinese President Xi Jinping warned his outgoing US counterpart, Joe Biden, not to cross the Taiwan "red line" as the two leaders met in Peru.

Xi Jinping reiterated to Joe Biden that China claims Taiwan as part of its sovereign territory.

While Washington avoids formerly recognizing Taipei at a diplomatic level, the US has become the self-ruled island's biggest security backer, sending billions in arms and military technology every year – to China's fury.

During Saturday's meeting, XI praised the "dialogue and cooperation" that took place under the Biden administration and said that "the relationship has remained stable on the whole."

China China's Xi warns of growing global "unilateralism" ahead of Biden meeting

"The two teams have worked out through consultations a number of guiding principles for China-US relations, and... have jointly brought China-US dialogue and cooperation back on track," Xi said, per Chinsese state-run news agency Xinhua.

"It is important not to challenge red lines and paramount principles," Xi reportedly told Biden, before restating Beijing's one-China principle.

"The Taiwan question, democracy and human rights, China's path and system, and China's development right are four red lines for China. They must not be challenged. These are the most important guardrails and safety nets for China-US relations."

According to the AFP, Xi also said he was ready for a "smooth transition" to President-elect Trump's administration.

The White House's account of the meeting was markedly different. It said that Biden condemned the deployment of North Korean troops to Russia, and put pressure on the Chinese leader to cease support for Moscow's war on Ukraine.

On Taiwan, the Democrat "underscored that the United States' one China policy remains unchanged."

"He reiterated that the United States opposes any unilateral changes to the status quo from either side, that we expect cross-Strait differences to be resolved by peaceful means, and that the world has an interest in peace and stability in the Taiwan Strait."

According to the White House, Biden also made a pointing of calling "for an end to destabilizing PRC military activity around Taiwan."