Frank Hsieh (R), Taiwan's de facto ambassador to Japan, is pictured with Joseph Young, charge d'affaires at the U.S. Embassy in Tokyo. (From Hsieh's Facebook page)(Kyodo)

TAIPEI - The temporary head of the U.S. Embassy in Japan visited Taiwan's representative at his official residence in Tokyo on Monday, the first time a U.S. diplomat has done so since Taiwan and the United States severed diplomatic ties 42 years ago.