China’s President Xi Jinping has warned U.S. President Donald Trump that Taiwan remains the most sensitive issue in relations between both countries, urging Washington to be careful with its arms support for the island.

The message came during a phone call between the two leaders on Wednesday, which Trump later described as “long and very positive.”

According to Chinese officials, Xi said China places great value on its relationship with the United States but stressed that Taiwan is a matter of sovereignty that Beijing will not compromise on.

“Taiwan belongs to China, and we must protect our territorial integrity,” Xi reportedly said, while calling on the U.S. to act cautiously when selling weapons to the island.

Trump, on his part, said his personal relationship with Xi remains strong and important for global stability.
“We both know how important it is to keep our relationship on good terms,” he wrote in a social media post.

The leaders also discussed global issues including Russia’s war in Ukraine, the situation in Iran, and trade relations. Trump disclosed that China is considering increasing its purchase of U.S. soybeans from 12 million to 20 million tonnes.

Tensions over Taiwan have long strained US-China relations. While China claims Taiwan as part of its territory, the island operates as a self-governing democracy and receives military support from the United States.

Last year, Washington approved a multi-billion-dollar arms deal with Taiwan, a move that angered Beijing and drew strong warnings from Chinese authorities.

Despite these tensions, relations between both countries have slightly improved in recent months following talks on trade, technology, and exports. Trump is also expected to visit China in April as part of efforts to strengthen diplomatic ties.

For now, Taiwan remains the biggest test of how far cooperation between the world’s two largest economies can go.