Obama approved an additional 13,000 more US troops to Afghanistan beyond the 21,000 he announced in March, The Washington Post reported.
The unannounced move includes engineers, medical personnel, intelligence experts and military police—the Post said, bringing the total buildup Obama has approved for the occupation to 34,000.
"Obama authorized the whole thing. The only thing you saw announced in a press release was the 21,000," a defense official familiar with the troop-approval process told the daily.
The report, posted on the newspaper's website late Monday, came as nhe Nobel Committee awarded him for "his extraordinary efforts" to strengthen international diplomacy and co-operation between peoples.
But the newspaper noted that the maximum number of US soldiers expected in Afghanistan by year's end -- 68,000 -- would remain the same.
Major deployments of support troops have not been publicized by the Pentagon and the White House in the past. When former president George W. Bush announced a US troop increase in Iraq, he only mentioned 20,000 combat troops and not the accompanying 8,000 support troops.
The troop increase approved by Obama brought the level of US forces deployed in the Iraq and Afghanistan theaters to a total greater than during the peak of the surge in Iraq in late 2007 and early 2008.
At the start of this month, some 65,000 US forces are currently in Afghanistan and about 124,000 in Iraq, compared to around 26,000 US troops in Afghanistan and 160,000 in Iraq at the height of the Iraq surge, according to a troop count by the Post.