WASHINGTON (CNN) -- The new chairman of the Senate Armed Services Committee, who opposes President Bush's plan to send more troops to Iraq, riticized the Iraqi government Friday for failing to live up to its promises time after time.

Sen. Carl Levin of Michigan made his comments at the start of a meeting to hear testimony from Defense Secretary Robert Gates and Peter Pace, chairman of the Joint Chiefs of Staff.

He questioned how the Iraqis would meet benchmarks under the plan Bush announced this week, when they haven't in the past. Major commitments by Iraqis -- most of which were to have been met by the end of 2006 -- were not carried out, according to Levin.

"That is not a track record that inspires confidence in Iraqi pledges and commitments," Levin said.

Asked about Iraqi ability to meet benchmarks, Gates said the United States will know fairly early whether the Iraqis are cooperating.

"If at that time we conclude that at a government level and on a broad level they have not met their commitment, then I think we have to evaluate our strategy," Gates said.