The Iraq Study Group report, to be released on Wednesday, will increase the pressure on President George W. Bush to adjust US military policy in Iraq to stem the rising violence and pave the way for an eventual troop withdrawal.

Leaks from the bipartisan commission led by James Baker, the former Republican secretary of state, and Lee Hamilton, a former Democratic congressman, suggest it will recommend a gradual withdrawal to step up pressure on the Iraqi government to clamp down on sectarian violence without outlining a timetable for a complete pull-out.