US Secretary of State John Kerry has intervened at the last minute to try to save a key security deal with Afghanistan.
Mr Kerry has offered to send a letter admitting past mistakes by the United States to a meeting of Afghan elders, a Loya Jirga, convened to consider the deal.
Talks have been going on to produce a document acceptable to both sides. If there is no deal, Washington will pull out all its troops in 2014.
International diplomats have become used to unpredictable changes in 12 years of dealing with President Hamid Karzai, the BBC reports.
Months of negotiations were nearly derailed by a late proposal from the Afghan side demanding that the future security deal should prevent US forces from entering Afghan homes.
But after a direct intervention on the phone from Mr Kerry, Mr Karzai has accepted an offer for President Barack Obama to write a letter acknowledging past US mistakes, and requesting that US forces should have the right to enter Afghan homes only in the case of "urgent risk to the life of US soldiers".
If that letter arrives, the deal will then be presented for approval by the Loya Jirga - of up to 3000 Afghan elders, which convenes on Thursday.
It is a last-minute compromise for a US government that had ideally wanted this deal signed months ago, so that American forces could plan for the period after combat operations end in 2014.
However, there are still hurdles ahead even if the compromise is accepted - including a disagreement over who has jurisdiction for any crimes committed by US forces remaining in Afghanistan after 2014.
Flexibility rejected
State Department spokeswoman Jen Psaki said the two sides continued to make progress, but added: "We're not there yet."
Earlier this week, a spokesman for Mr Karzai told the BBC that there was no flexibility possible in the stand taken by his government over US forces entering Afghan homes and mosques.
He said President Hamid Karzai felt very strongly about this, and would not accept any agreement that would allow US forces to enter Afghan homes for what he called "the purpose of aggression".
Mr Karzai and other Afghan leaders have long maintained opposition to US raids on Afghan homes - a highly sensitive issue throughout the country.
Night raids are particularly offensive because they are perceived as violating the sanctity of women in the house.
The US has insisted that such powers are necessary to prevent terrorist attacks coming from Afghanistan.
