BBC interviews Petraeus
Time running out
Gen Petraeus is due to return to Washington in September to report on the campaign's progress.
However, correspondents say the clock in Washington is running fast.
In recent days four Republican senators have withdrawn support for President George W Bush's Iraq strategy, adding their voice to a growing number calling for a new plan.
And this week will see a contentious debate in the US Senate over a major defence spending bill.
On Sunday the Pentagon announced that US Defence Secretary Robert Gates was cancelling a planned Latin American tour in order to focus on the upcoming clash.
According to BBC world affairs editor John Simpson, the debate is moving so fast in Washington that Gen Petraeus's efforts, which might have saved the day for the Bush administration if they had been introduced three, or even two, years ago, may well have come too late.
I have noticed that Democratic efforts to kill the war seem to rise in proportion to reports of progress, or changes in tactics. The last attempt to shut it down began just about the same time as the surge started deploying. A cynic might think they are a hell of a lot more worried about a possible success than a failure.
