U.S. Ambassador to Iraq Ryan Crocker, right, accompanied by Gen. David Petraeus, testifies on the future course of the war in Iraq on Tuesday during a hearing of the Senate Foreign Relations Committee.

Washington ? Facing the senior U.S. commander and top U.S. diplomat in Iraq on a second day of testimony before Congress, several Senate Republicans expressed deep skepticism, frustration and unease with the current American path and little enthusiasm for leaving troops in the war-torn country indefinitely.

Gen. David Petraeus and U.S. Ambassador Ryan Crocker spent more than 10 hours Tuesday testifying and answering at-times pointed questions from senators on the Foreign Relations Committee and the Armed Services Committee about the military, political and diplomatic status of Iraq – a topic that President Bush also will address in a prime-time speech Thursday.

Democratic leaders said after meeting with Bush on Tuesday afternoon that they would push for even greater troop reductions. But they also said they are dubious that they will be able to corral enough Republican votes to force a change of course.

Still, GOP lawmakers – including some of the party’s most respected voices on foreign policy – demonstrated at the hearings that they are not quietly following the White House script. In some instances, their criticism was almost as scathing as that of the most hostile Democrats.

“It is not enough for the administration to counsel patience until the next milestone or the next report,” warned Sen. Richard Lugar, R-Ind., the ranking member of the foreign relations panel, as he ticked off the sectarian and tribal divisions likely to stymie progress. “We need to see a strategy for how our troops and other resources in Iraq might be employed to fundamentally change the equation.”