"US forces will more proactively support Afghan conventional forces," a senior administration official told AFP.
The official, who asked not to be named, sketched plans to provide more close air support and to accompany Afghan forces on the battlefield.
"This does not mean a blanket order to target the Taliban," the official cautioned.
Obama came to office in 2008, promising to end one of America's longest and most grueling wars.
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More than 2,000 US personnel have died in the ensuing war.
There are still 9,800 US troops in the country, down from a peak of around 100,000 in March 2011.
US forces are mainly confined to ministries or bases. Only special forces assist their Afghan counterparts on the battlefield.
But the campaign to neutralize the Taliban has suffered multiple setbacks in the twilight of Obama's presidency.
Afghanistan's fledgling security forces have struggled in the face of bloody Taliban assaults.
Afghan authorities on Wednesday recovered the bullet-ridden bodies of 12 security officials captured by the Taliban in eastern Ghazni province. Gunmen kidnapped 40 others.
Local support for US efforts has been undermined by the unintended killing of Afghan civilians.
Last year, missile strikes on a hospital in Kunduz killed 46 people and prompted worldwide outrage.
At the same time, diplomatic efforts to engage the Taliban appear to have broken down.
The United States killed Taliban leader Mullah Akhtar Mansour in a drone strike in Pakistan last month.
"We anticipate the Taliban will continue an agenda of violence," he said during a visit to Japan.
Obama's latest troop decision would appear to push any brokered solution well beyond his presidency.