Democratic presidential candidate Barack Obama said on Saturday his plan to end the Iraq War was unchanged and he was puzzled by the sharp reaction to his statement this week that he might "refine" his timetable for withdrawing US combat troops.

"For me to say that I'm going to refine my policies I don't think in any way is inconsistent with prior statements and doesn't change my strategic view that this war has to end and that I'm going to end it as president," Obama told reporters on his campaign plane.

Obama, who based his drive to capture the Democratic nomination on his early and ardent opposition to the war, said earlier last week he might alter his plan to bring combat troops home within 16 months of taking office if conditions on the ground changed.