Senator Chuck Hagel, R-Neb., is putting off a decision about a possible presidential bid.
The Nebraska Republican has been an outspoken critic of the Iraq war.
Hagel told a press conference today in Omaha that he wants to keep his focus on finding "a responsible way out of this tragedy."
Hagel, who said in 2004 that he may make a White House run, now says he'll decide about his political future later this year.
Hagel's staunch opposition to the administration's Iraq policy is shaped in part by his experience as an Army sergeant in Vietnam, where he served side-by-side with his brother Tom.
He was twice wounded in 1968, one of the bloodiest years of the war, earning two Purple Hearts.