The US dollar weakened to the mid-163 yen range in Tokyo trading this morning, following reports that the United States and Iran temporarily halted attacks on each other over the weekend. As of noon Tokyo time, the dollar was trading at 163.57 to 163.58 yen, compared with 163.82 to 163.92 yen in New York and 163.76 to 163.78 yen in Tokyo at 5 p.m. Friday. The euro traded at 1.1406 dollars and 186.57 to 186.58 yen, against 1.1364 to 1.1374 dollars and 186.26 to 186.36 yen in New York, and 1.1388 to 1.1391 dollars and 186.51 to 186.55 yen in Tokyo late Friday.