WASHINGTON (AP) - Iraqi ground forces should become proficient by mid-2009, possibly as early as April, an Army general told Congress on Wednesday.

The assessment by Lt. Gen. James Dubik suggests that U.S. troops could start stepping back around that time from ground combat missions, the most dangerous in Iraq. Dubik, who for the past year led efforts to train Iraq's army and police units, said his estimate depended on several factors and did not take into account when other components of Iraq's security forces would become more independent.

Overall, Iraq's security forces have control of just half its 18 provinces. While the Defense Department recently estimated Iraq could take the lead in all the provinces by the end of this year, other military officials have said 2009 is more realistic.

"Declaring full success too early is a risk," said Dubik, who is retiring after 37 years of service. "There has been huge progress. There has been significant improvement in every possible way you can measure it. But full success is not yet at hand."

Dubik said Iraq's security forces have grown from 444,000 to 566,000 since he assumed command of the Multi-National Security Transition Command in June 2007. They are better able to execute operations on their own, he said.

But the fast-growing force lacks experienced leaders and the ability to train all its recruits. More specifically, Iraq's military forces does not have the aviation and other specialized capabilities that "are not going to be fixed in the short term," he said.

Lawmakers pressed Dubik about when he thought the Iraqis could take more control.

"In your opinion, when will the Iraqis be able to handle their own security so our troops no longer have to do it?" asked the chairman, Rep. Ike Skelton, D-Mo.

"I would not put an `X' on the calendar, Mr. Chairman," Dubik answered. One reason, he said, is that the Iraqis have yet to decide on critical military purchases, including aircraft.

When Skelton asked Dubik to consider ground forces only, the general said it would be in the middle of next year before they would be considered fully capable.

"It could be as early as April. It could be as late as August," he said.

The Iraqi military said Wednesday that the number of "terrorist attacks" in June declined 85 percent from the same period a year ago. Despite the security gains, frequent attacks continue throughout the country.

When Dubik testified before Congress in January, he said Iraq was on track to reach some 580,000 security force members by the end of the year but that the forces still were a long way from becoming self-sufficient. Iraqi officials estimated to him that the country probably would not be able to assume responsibility for internal security until sometime between 2009 and 2012, or defend its borders before 2018, he said.

In his testimony Wednesday, Dubik said believes that 2009 to 2012 window is still accurate.

Army Lt. Gen. Frank Helmick assumed control of the U.S. training command last week.

On the Net:

House Armed Services Committee: http://www.house.gov/hasc/

Background on Dubik: http://tinyurl.com/5fh45k