The United States will withdraw another 4,000 troops from Iraq by the end of October, the top U.S. commander in Iraq said in prepared remarks to be delivered to a congressional hearing later Wednesday.

Gen. Ray Odierno, the U.S. commanding general in Iraq, will also tell the House Armed Forces Committee that as violence has dropped in Iraq, the U.S. military is on track to end its combat mission in Iraq by next year, according to his statement released to the media prior to the hearing.

"We have approximately 124,000 troops and 11 Combat Teams operating in Iraq today. By the end of October, I believe we will be down to 120,000 troops in Iraq," he said in the remarks.

Odierno said statistics show violence has dropped in Iraq.

"Overall attacks have decreased 85 percent over the past two years from 4,064 in August 2007 to 594 in August 2009, with 563 in September so far," the general said.

"In that same time period, U.S. military deaths have decreased by 93 percent, (and) Iraqi Security Force deaths have decreased 79percent," he added.

However, Odierno said there were still security concerns.

"Although overall security is improving, it is not yet enduring. There still remain underlying, unresolved sources of potential conflict," the general said.

Odierno pointed to the Aug. 19 bombings in Baghdad that targeted the Ministries of Finance and Foreign Affairs that killed more than 100 people as an example of ongoing challenges in Iraq.

Nevertheless, the general gave a vote of confidence to the Iraqi forces who have already taken over security for Baghdad after U.S. forces handed over control.

"The Iraqis wanted to be in charge; they wanted the responsibilities; and they have demonstrated that they are capable," he said.

Chairman of the House Armed Forces Committee Ike Skelton, in response, said in a statement that moving U.S. troops and equipment out of Iraq "will not be easy for us or, I suspect, for the Iraqis."

"The war in Iraq is coming to a close, but my suspicion is that these transitions will take years to work through."

After taking office in January, U.S. President Barack Obama announced that the U.S. combat mission in Iraq will end by Aug. 31,2010.

The president also said he plans to keep a range of 35,000 to 50,000 support troops on the ground in Iraq after combat troops are out.

All U.S. troops will leave Iraq by the end of 2011, according to an agreement reached by the two countries last year.