Speaking to reporters on Thursday after returning from a trip that included a one-day stop in Baghdad, (Republican Senator, and Chairman of the Senate Armed Forces Committee) Mr. Warner said the United States should consider “a change of course” if the violence there did not diminish soon. He did not specify what shift might be necessary, but said that the American military had done what it could to stabilize Iraq and that no policy options should be taken “off the table.”

With the blessing of the White House, a high-level commission led by James A. Baker III, the former secretary of state, is already reviewing American policy in Iraq. But the commission is not scheduled to report to Mr. Bush and Congress until after the November elections, a timeline that the White House had hoped would enable Mr. Bush to avoid public discussion of any change of course until after voters determine which party will control Congress next year.