The top Democrat in the US Senate on Thursday fired off unusually frank criticism of the generals running operations in Iraq, in an acerbic aside to his quarrel with the White House over the war.

Majority leader Harry Reid said he was disappointed in Marine General Peter Pace, outgoing chairman of the Joint Chiefs of Staff, and hoped for a more candid approach from General David Petraeus, US commander in Iraq.

The comments by Reid, who sparked the ire of the Bush administration by declaring in April that the “war is lost,” appeared to reflect a day-by-day strategy by Democrats to crank up political heat over the war.

On Wednesday, Reid bluntly told Bush in a letter also signed by House of Representatives speaker Nancy Pelosi that his troop “surge” strategy in Iraq was failure, a day after vowing to launch a new bid to change US war policy.

In a news conference, Reid did not confirm he had branded Pace “incompetent” in an interview with liberal bloggers, as reported by the Politico newspaper, but left no doubt about his views of the top US soldier.

“I told him how I felt, that he had not done a very good job in speaking out for some obvious things that weren’t going right in Iraq. I told him that to his face.”

Earlier in the week, Defense Secretary Robert Gates said he would not nominate Pace for a second two-year term, in order to avoid a divisive showdown in Congress over the war.

The White House meanwhile focused on Reid’s reported comments that Pace was “incompetent.”

“I certainly hope it’s not true, because in a time of war, for a leader of a party that says it supports the military, it seems outrageous to be issuing slanders toward the Chairman of the Joint Chiefs,” said White House spokesman Tony Snow.

“I don’t know if it’s true or not. If it is true, I certainly hope he does apologize.”

Reid also had caustic words for Petraeus, saying although he had high regard for the general, he believed his past assessments of the US effort to build the Iraqi army were too rosy.

“He told us it was going great. As we’ve looked back, it didn’t go so well,” Reid told reporters.

Reid also expressed disappointment about a newspaper interview, in which Petraeus was quoted as perceiving “astonishing signs of normalcy” in half or perhaps two-thirds of Baghdad.

“I was a little disappointed, to say the least, today reading USA Today newspaper where he’s saying things are going fine, kids are playing soccer,” Reid said.

“I think you would come to the conclusion that this view of what’s going on in Iraq is different than what most everyone else is saying, including other accounts today.

“So I am waiting to see if General Petraeus can be a little more candid with us. What took place in USA Today is not being very candid.”

The United States has just completed an operation to send 30,000 more troops into Iraq as part of a strategy announced by Bush in January to bring down violence in Baghdad and in the restive, Sunni-majority Al-Anbar province.

Bush said Wednesday after speaking to Petraeus that “the final troops have just arrived,” reporting “some progress and some setbacks.”

But a Pentagon report to Congress released Wednesday said overall violence in Iraq had not decreased despite the new “surge” strategy.

The latest aggravation between Congress and the White House over Iraq came days after the US military mourned its 3,500th soldier killed in action and followed another bomb attack by suspected Al-Qaeda militants on a revered Shiite shrine in the Iraqi town of Samarra.

Congress-White House sparring is building up ahead of the next critical point in the political struggle over Iraq in September, when Petraeus is due to report on progress in the “surge.”

Even senior Republicans have said they expected the president will have little choice but to make adjustments in the Iraq strategy, once the report is made public.