The dollar was steady on Friday, on course for weekly rise, while the euro dropped to three-month trough after the European Central Bank prolonged its bond purchases and eased the chances that it would increase interest rates next year.
The dollar index inched up 0.2 percent to 94.800, its three-month top, poised for a weekly surge of 1.1 percent.
The greenback advanced 0.15 percent to 114.155 yen, heading for a weekly rise of 0.5 percent.
The euro lost 0.15 percent to $1.1633 after sliding to $1.1624, its trough since July 26. It was 1.3 percent lower for the week.
The pound tumbled 0.3 percent to $1.3124, with investors focused on first interest rate hike in more than a decade.