Lugar says the president may pay a big political price if he doesn't. He also says Syria and Iran should join diplomatic efforts to end sectarian violence in Iraq, as well as the Saudis, the Jordanians, the Turks and others.

Bush is believed to be considering a "temporary surge" of 10,000 to 30,000 U.S. troops to stabilize Baghdad and the rest of the country.

Appearing on "Fox News Sunday," Lugar, the outgoing chairman of the Foreign Relations Committee, was asked whether he supported an increase. "Well, I don't know whether I do or not," he said, "but if the president just advises congressional leaders of his decision "he can anticipate not endless hearings, but a lot of hearings, a lot of study, a lot of criticism ... demands for subpoenas, all sorts of situations in which administration figures perhaps reluctantly come to the (Foreign Relations Committee), or don't come to the committee."

Lugar also told Fox News he did not think the weekend execution of former Iraqi dictator Saddam Hussein would have much effect on sectarian violence.