The early deployment of an additional Army aviation brigade to Iraq means the surge of additional U.S. forces into the country now approaches 30,000 troops.
The original estimate of 21,500 ground combat troops making up the surge into Baghdad and Al Anbar Province has been steadily rising these past weeks.
The increase reflects the reality of providing logistical support to the 21,500 ground combat troops originally estimated as making up the surge.
Some 2,600 soldiers from the 3rd Infantry Division's Aviation Brigade will now deploy to Iraq in May, 45 days ahead of schedule.
The unit will provide transport helicopters and gun ships to assist ground brigades when they arrive in Iraq. There are currently three other Army aviation brigades serving in Iraq.
Last month, Pentagon officials, including Defense Secretary Robert Gates, downplayed a Congressional Budget Office estimate that the surge would require an additional 28,000 "enablers," saying a more realistic number would be around 2,400.
But that number has risen to between 7,000 and 8,000 in recent weeks because of additional troop requests by Gen. David Petraeus, the new commander of U.S. forces in Iraq.
Shortly after taking command last month, Petraeus asked for 2,200 additional military policemen to deal with the anticipated spike in the number of insurgent detainees as the surge progresses.
He also asked for "additional lift" capability for the growing number of combat brigades in the Baghdad area. Sending the aviation brigade earlier in May would provide greater flexibility for the additional combat troops that would have completed the surge into Baghdad by then.
A Defense official said there are no other pending requests for more troops to assist with the surge, but it is preparing for additional requests if they come.
According to former Acting Army Chief of Staff and ABC News consultant Jack Keane, the additional support troops are necessary for the fight. "Those combat brigades do not perform without the support troops that they need. We're talking about aviation, intelligence, military police, engineers, communicators."
A major proponent of the surge, Keane co-wrote an American Enterprise Institute study that called for a surge of 30,000 combat troops.
Keane said the Pentagon should have been more upfront in announcing the total number of troops that would be ultimately required for the surge. "They should have added in the enablers to the combat troops right from the beginning, put that out as 35,000 level of surge based on commanders needs and be done with it."
Last month Defense Secretary Robert Gates said he expected the surge lasting "in terms of months, rather than 18 months or two years."
But military planners already face a crucial "decision point" by mid-April on whether to sustain the top level of the surge past September and well into the coming year.
Planners need enough lead time to begin notifying the replacement units that would maintain current troop levels.
In the meantime, Army officials have said they are likely to call on National Guard combat brigades to ease the strain on their active duty forces.