China demanded Tuesday that the United States (US) "immediately cancel" a potential sale of US$2.2 billion in arms to self-ruled Taiwan, including battle tanks and anti-aircraft missiles, adding fuel to tensions between the two powers.The US later shrugged off China's complaints, responding that the equipment would contribute to "peace and stability" in Asia.The sale would be the first transfer of big-ticket US military gear to the democratically-governed island in de