TAIPEI (Reuters) -Taiwan should pay the U.S. for its defence as it does not give the country anything, Republican presidential candidate Donald Trump told Bloomberg Businessweek, sending shares of Taiwanese chip manufacturer TSMC lower on Wednesday. The United States is Taiwan's most important international supporter and arms supplier, but they have no formal defence agreement, unlike what Washington has with South Korea and Japan. The U.S. is, however, bound by law to provide Taiwan with the means to defend itself.