Beijing appealed to Washington on Thursday to stop selling rival Taiwan advanced weapons, as a top American admiral visited in hopes of improving US-Chinese military ties. The United States should "cease the sale of advanced weapons to Taiwan and military exchanges," said Liu Jianchao, a Foreign Ministry spokesman. Taiwan and China split in 1949, but the communist mainland claims the self-ruled island as part of its territory. China threatens regularly to invade. The United States has no official relations with Taiwan but is the island's main weapons supplier and military protector.