WASHINGTON - US President-elect Donald Trump's phone conversation with Taiwan President Tsai Ing-wen, which prompted a diplomatic protest from China, was simply a 'courtesy call,' Vice President-elect Mike Pence said on NBC on Sunday. Asked whether any shift in policy should be read into the call, Pence said: 'I don't think so.' The call was the first by a US president-elect or president since President Jimmy Carter switched diplomatic recognition from Taiwan to China in 1979.