The marine died Saturday "of wounds sustained from an enemy improvised explosive device attack on his vehicle during combat operations," the statement said.
The marine was killed in fighting in the town of Nasser Wa Salaam, near Fallujah, some 50 kilometers (30 miles) west of Baghdad.
The town is located in the restive Sunni Arab province of Al-Anbar in western Iraq, where marines and US soldiers have been battling insurgents for months.
The latest deaths brought to 2,014 the number of US military personnel killed in the Iraq operation since the March 2003 invasion, according to an AFP tally.