American fatalities in Iraq in September are the lowest monthly death toll in more than a year.
Overall last month, 63 Americans died, according to the latest Defense Department releases.
A U.S. soldier was killed Sunday in a small-arms attack during combat operations in eastern Baghdad, the military said Monday. The soldier, whose name was withheld pending notification of relatives, was assigned to the Multi-National Division-Baghdad.
The death toll is the lowest since July 2006, when 43 Americans died in Iraq.
In September, 41 troops died in combat and 21 died from non-hostile causes. In August, 84 U.S. troops died, 62 of them in combat.
U.S. commanders attribute the reductions in fatalities to a new U.S. strategy backed by 30,000 additional American troops. They say the boost in troops has taken the initiative from al-Qaeda and increased security in the capital and other parts of Iraq. There are about 160,000 troops in Iraq.
"With a decreasing number of attacks, you get less casualties," said Brig. Gen. John Campbell, an assistant commander for the U.S. division in Baghdad.
Although there has been a recent increase in suicide bombings in the Baghdad area, they have not produced mass casualties, he said. Overall, attacks on Iraqi and coalition forces and sectarian killings have steadily declined in Baghdad, he said.
Average monthly attacks on civilians and Iraqi and coalition forces fell to less than 4,000 in August from more than 5,000 in May, according to a Pentagon report to Congress released in September.
According to the U.S. military, more of Baghdad's neighborhoods are free of enemy activity since the additional troops first began arriving in February.
The military rates the level of security in each of the capital's 474 neighborhoods.
The rankings consider the level of enemy activity and capabilities of Iraqi security forces. The levels range from "disrupt," in which coalition forces conduct operations to keep militants off-balance, to "retain," a condition in which insurgents have been cleared from the neighborhood and Iraqi security forces are capable of keeping the area secure.
Starting this year, U.S. and Iraqi troops have pursued a strategy that moved soldiers off large bases and created combat outposts manned by Americans and Iraqis. American and Iraqi forces also have launched large offensives in and around the capital designed to target al-Qaeda and prevent its members from regrouping elsewhere.
"We've done a very good job on al-Qaeda," Campbell said in a telephone interview from Iraq. "I think we've got them on the run."
Campbell said a cease-fire called recently by radical Shiite cleric Muqtada al-Sadr has also contributed to declining violence, though not all Shiite militia groups heeded his call.
American casualties increased this year after the strategy was launched. American and Iraqi forces began operating in areas that had been al-Qaeda sanctuaries, sometimes meeting stiff resistance.
From March through June, 411 Americans died in Iraq, including 126 in May, according to a USA TODAY database.
Some critics of the White House's strategy, such as Sen. Carl Levin, D-Mich., question whether the gains can be held without a heavy American presence since Iraq's government has taken little action to build consensus and eliminate the conditions that breed sectarian and insurgent violence.
A report issued last week from the Government Accountability Office says the Pentagon data may not capture violence produced by militia attacks on each other. It recommends the Pentagon produce more frequent and detailed reports.
"I don't want to give the false impression that we're all doing high fives," Campbell said. "It takes continued presence."
Contributing: Paul Overberg