The top U.S. military commander in Iraq said Wednesday that the U.S. military could begin a substantial troop pullout as early as next spring.

Gen. George Casey, who spoke to reporters during Defense Secretary Donald Rumsfeld's unannounced trip to Iraq, said some conditions would have to be met for the withdrawal to take place.

"I do believe that if the political process continues to go positively and if the development of the security forces continues to go as it is going, I do believe we'll still be able to take some very substantial reductions after these elections in the spring and summer of next year."

Elections in Iraq are scheduled for the end of this year.

Casey said he could not say how many of the approximately 135,000 American troops would be withdrawn.

At the same time, transitional Prime Minister Ibrahim al-Jaafari, who met with Rumsfeld, said it was time for a coordinated plan to transition from the American to the Iraqi military and urged that it be done in a speedy fashion.

According to a recent CNN poll, 60 percent of Americans say they don't believe the United States will be able to establish a permanent government in Iraq. In addition, a Pentagon report issued last week said 171,000 Iraqi security forces are now trained and equipped but that only 2,500 are capable of mounting counter-insurgency operations on their own without Coalition Forces help.

Source: Agencies