Top U.S. military officials say early progress is being made in the effort to quell violence in Baghdad, but they are warning the plan will take several months to unfold and that quick, dramatic results should not be expected.  VOA correspondent Meredith Buel has details from Washington.

An Iraqi army soldier searches the trunk of a passenger car at a vehicle checkpoint in central Baghdad, Iraq

President Bush's new strategy for Iraq calls for sending more than 20,000 additional troops to the country, with most being deployed in Baghdad.

The operation got under way this week, and eventually more than 90,000 Iraqi and American soldiers will be operating in the city.

Army Lieutenant General Douglas Lute, director of operations for the Joint Chiefs of Staff, told reporters at the Pentagon he is pleased with the way the mission has begun.

"Early progress has been made," he said.  "We are beginning to see good, solid evidence across all the lines of commitment made by the Iraqi government, but it is very early in the operation.  We are just in the opening days. So, in summary, so far so good, but we are in the very early days of what will be a very deliberate campaign that will unfold only over several months.  We should not expect quick, easy or dramatic results."

General Lute says the Iraqi government has begun to meet its commitments to increase troop strength in Baghdad by an additional three brigades.  Lute says one brigade has arrived in the capital, and the other two will deploy later this month.

U.S. officials say the lead Iraqi brigade arrived at 60 percent of its full strength, something Mark Kimmitt, the deputy assistant secretary of defense for the Middle East, calls adequate. 

"There was never an expectation that these units would come in at 100 percent," said Mr. Kimmitt.  "Thus far, the units that are coming in are coming in at adequate levels for them to perform the Baghdad security plan.  The number that they come with was fully anticipated by the planners and it is still within the range that they believe is going to prove successful in the Baghdad security plan."

In the past several weeks, six U.S. helicopters, four flown by the military and two by contractors, have crashed in Iraq.

General Lute says four were believed to have been shot down by enemy fire, one was brought down by mechanical problems and one crashed due to pilot error.