Chinese President Xi Jinping warned his US counterpart Joe Biden on Friday that the Taiwan issue must be handled properly to avoid harming relations, according to Chinese media. 

China claims that Taiwan is the most sensitive and crucial subject in its dealings with the United States and that it should be brought back into the fold by force if necessary.

Washington has no official diplomatic ties with Taipei but is Taiwan's major international patron and arms supplier.

"Some individuals in the United States are sending the wrong signals to pro-independence forces in Taiwan, and that's very dangerous," Xi told Biden during a video call.

"If the Taiwan issue is not handled properly, it will have a subversive impact on the relationship between the two countries."

Shandong sails through the Taiwan Strait

China sailed its aircraft carrier Shandong through the Taiwan Strait on Friday, shadowed by the US destroyer, a source with direct knowledge of the situation told Reuters, just hours before the Chinese and US presidents were scheduled to meet.

Biden repeated in his talk with Xi that the United States' position toward Taiwan has not changed and that Washington "continues to oppose any unilateral alterations to the status quo", according to a White House statement.

China has increased its military activities near the island in the last two years to assert its sovereignty claims.

Biden urged China to take meaningful steps in response to Russia's military operation in Ukraine. Taiwan has joined Western-led sanctions on Russia and has offered humanitarian aid to Ukrainian refugees.

According to Chinese official media, Xi also warned Biden that the fighting in Ukraine must stop as soon as possible.

All parties should support the Russia-Ukraine dialogue, while the US and NATO should also hold discussions with Russia to resolve the "crux" of the Ukraine problem, according to Xi.

Xi, Biden phonecall 

On Friday, upon Joe Biden's request, Chinese President Xi Jinping and his US counterpart spoke during a  2-hour long video call Friday evening about the current Ukraine crisis. 

China and the United States, according to Xi, should share international responsibilities and work for world peace and tranquility. 

The video conference was the first since last November's virtual summit when the two presidents exchanged views on Chinese and US relations and matters of mutual interest.

Xi, noting the serious challenges that the world is facing right now, said that the world is neither tranquil nor stable and that the Ukraine crisis is not something that Beijing wants to see.