Two US soldiers were killed in separate roadside bomb blasts in Iraq on Wednesday, one in eastern Baghdad and the other near the town of Balad north of the capital, the US military said.
The number of wounded in Iraq, according to Defence Department records as of 14 August, stands at 6497, but unofficial sources put that number above 6900.
August marked the highest toll - 66 - for US forces since May 2004, as US-led troops engaged in fierce battles with forces loyal to Shia leader Muqtada al-Sadr in southern Iraq.
In April 2004, US forces suffered 135 fatalities during the siege of Falluja.
In a televised press conference at the Pentagon shortly before the 1000-mark was reached, US Secretary of Defence Donald Rumsfeld justified the mounting US military death toll.
"Taking the offence, however, of course, has its cost, just as staying on defence has its cost," he said.
"In the global war on terror, we've
lost well more than 1000 already"
"When combined with US losses in other theatres in the global war on terror, we have lost well more than 1000 already," he said.
Rumsfeld's press conference, his first at the Pentagon since mid-July, came amid fierce fighting in Baghdad between US forces and al-Mahdi Army fighters loyal to al-Sadr that left three US soldiers and more than 40 Iraqis dead.