The death of a Texan soldier in Baghdad brings the total number of US troops killed in Iraq to 3,000, independent groups tracking casualties have said.
Donica's death brought the toll to the 3,000 mark
The US Defence Department confirmed that the soldier was killed by small arms fire in the capital last week.
The announcement came on the final day of 2006 and as the US military reached the end of the deadliest month for its troops in Iraq for two years.
The US president is considering the future strategy for troops in Iraq.
The figure was calculated by an independent website, Iraq Coalition Casualty Count, and by the Associated Press news agency.
US soldiers have faced massive opposition from insurgent groups
The Pentagon confirmed the death of 22-year-old Dustin R Donica on 28 December as previously unreported.
"Every loss is regretted and there is no special significance to the overall number of casualties," Lt Col Mark Ballesteros said.
The BBC's Jonathan Beale, in Washington, says this grim milestone comes at a critical time for Mr Bush as he prepares to unveil a new strategy in Iraq, which may include increasing the number of soldiers on the ground.