Taliban militants have stepped up their attacks against the US-led forces
The US military in Afghanistan is to be allowed to pay Taliban fighters who renounce violence against the government in Kabul.
The move is included in a defence bill which President Obama has signed.
Such payments have already been widely used by US commanders in Iraq, but it is the first time the system is being formally adopted in Afghanistan.
Early on Wednesday, Afghan troops were engaged in a shootout with suspected militants at a house in Kabul.
A day earlier eight US soldiers were killed in bomb attacks in southern Afghanistan.
The deaths make October the deadliest month for American forces in the eight-year war in Afghanistan.
President Obama is yet to decide whether to send thousands more troops to Afghanistan.
Mr Obama has said he will not risk their lives "unless it is absolutely necessary".
The latest attacks come amid heightened tension in Afghanistan in the run-up to the second round of a presidential election marred by widespread fraud in favour of incumbent President Hamid Karzai.
The Commander's Emergency Response Programme, or Cerp, was set up to give the US military the means to clear roads, dig wells and provide other urgent humanitarian assistance to the people of Iraq and Afghanistan, the BBC's Richard Lister in Washington says.
Foreign forces in Afghanistan are sustaining heavier casualties
But in Iraq, the money can also be given to insurgents provided they switch sides.
Backers of the Cerp scheme say it enabled some 90,000 formerly hostile Iraqis to form local militias and protect their towns from militants, our correspondent says.
He adds that now the same authority is being given to US commanders in Afghanistan.
A clause in the annual defence appropriations bill says they can use the money to support the "re-integration into Afghan society" of those who have renounced violence against the Afghan government.
Although $1.3bn (£691m) has been authorised for the fund as a whole, no specific sum has been allocated to the re-integration programmes, our correspondent says.
The Senate Armed Services Committee chairman, Senator Carl Levin, has said he envisages the money being used to pay former Taliban fighters to protect their communities.