Defense Secretary Robert Gates on Friday raised the possibility of cutting U.S. troop levels in Iraq to 100,000 by the end of next year, well beyond the cuts President George W. Bush has approved. Stressing that he was expressing his hope, not an administration plan, Gates said it was possible conditions in Iraq could improve enough to merit much deeper troop cuts than are currently scheduled for 2008. Asked at a news conference whether he was referring to going from today's level of about 169,000 to about 100,000 U.S. troops by the end of next year, Gates replied, «That would be the math.» It was the first time a member of Bush's war cabinet had publicly suggested such deep reductions, although many in Congress have pushed hard for big cuts to begin bringing the war to a conclusion. Bush announced Thursday that he had approved a plan recommended by Gen. David Petraeus, the top U.S. commander in Iraq, to reduce troop levels from the current 20 combat brigades to 15 brigades by July. Gates said it was too early for Petraeus or others to forecast with confidence any additional cuts.