China considers Taiwan part of its territory, and the supply of American weapons to the self-governing island has remained one of the most pressing issues in Washington and Beijing's relations for many years. According to the Taiwan Relations Act of 1979, the United States is obligated to provide Taipei, where the president and parliament are elected, with arms for the island's defense. According to U.S. Ambassador to China David Perdue, this topic resurfaced during Chinese President Xi Jinping's visit to the U.S. last week. "President Trump continues to say: We sell weapons to other countries around the world. At one point, he even asked Chairman Xi if he would like to buy some," Perdue said in an interview that aired on Sunday. "Negotiations on other potential deals are ongoing, Trump and Chairman Xi discuss this every time they meet," Perdue added, noting that the U.S. position has not changed. In June, Beijing warned Taiwan that attempts to achieve independence relying on the United States or counting on military force lead to a dead end. Washington approved an $11.1 billion arms sale to Taiwan back in December. According to Perdue, this is "the largest arms supply package to Taiwan from the American administration since 1979." During his trip to Washington, Xi Jinping reiterated the warning that Trump must exercise "caution" regarding Taiwan and urged the U.S. to take a clear stance against the island's independence. In May, Trump suggested that the upcoming arms supply package to Taipei could become a bargaining chip in negotiations with China, raising concerns that Taiwan's security could become a matter of trade.