"I don't understand why if the president has been talking about him," his mother, Rosa Peralta, told the newspaper, which was the first to report the bestowing of the Navy Cross.
Rosa Peralta said she was informed during a meeting with Marine Corps Lt. Gen. Richard Natonski that a committee could not agree on awarding the Medal of Honor to her son, who Marine Corps officials say was first wounded by friendly fire. She said the general mentioned the friendly fire aspect as part of her son's death during the discussion.
Marine Corps spokesman Mike Alvarez confirmed the meeting, saying only that it was a personal briefing between Natonski and Rosa Peralta to inform her that the secretary of the Navy would award the Navy Cross posthumously for extraordinary heroism.
The Navy Cross is the second highest honor for combat heroism a Marine can receive.
The secretary of the Navy's public affairs office in Washington, D.C., did not immediately return an after-hours telephone call Wednesday seeking comment.
Headquarters Marine Corps spokesman Maj. David Nevers told The Associated Press that the Navy Cross for Peralta "is not bestowed lightly."
Nevers said only 23 sailors and Marines out of the thousands who have served in combat in Iraq and Afghanistan have received the Navy Cross.
"The awarding of a medals of valor is a methodical process and carefully conducted to ensure the sacrifice and service of our Marines and sailors is appropriately honored," he said.
Peralta was shot several times in the face and body during a house-to-house search in Fallujah on Nov. 15, 2004, during some of the fiercest fighting of the war.
According to a report by a Marine combat photographer who witnessed the act, Peralta lay wounded on the floor of a house and grabbed a grenade that had been lobbed by an insurgent. He absorbed the blast with his body, dying instantly.
In 2005, Natonski, then-commanding general of the 1st Marine Division, ordered an investigation to determine the source of a bullet fragment recovered from Peralta's body.
"Following multiple and exhaustive reviews, the evidence supports the finding that Peralta was likely hit by 'friendly fire,'" the Marine Corps said Wednesday in a press release. "This finding had no bearing on the decision to award the Navy Cross medal."
Bush cited Peralta's heroism in a Memorial Day speech in 2005, saying the Marine "understood that America faces dangerous enemies, and he knew the sacrifices required to defeat them."
Peralta, who was assigned to Hawaii's 1st Battalion, 3rd Marine Regiment, moved to San Diego from Tijuana as a teenager. He was 25.