The United States is to extend its military presence in Afghanistan beyond 2016, administration officials say.
President Barack Obama will outline the plans later. They are expected to include keeping 5,500 troops in the country when he leaves office in 2017.
Originally all but a small embassy-based force were due to leave by the end of next year.
But the US military says more troops will be needed to help Afghan forces counter a growing Taliban threat.
There are currently 9,800 US troops stationed in Afghanistan. Last week, the top US military commander in Afghanistan, Gen John Campbell, said the US must consider boosting its military presence there beyond 2016.
The US forces will be stationed in four locations – in Kabul, Bagram, Jalalabad and Kandahar.
The slowing of the withdrawal of US troops from Afghanistan means that President Obama will not be able to bring home all US forces before his presidency ends.
A US review of its troop presence there has been under way for some months and is not directly linked to the Taliban’s recent success in briefly seizing the town of Kunduz.
But that episode illustrated the continuing need for the US training and mentoring of Afghan forces.
With al-Qaeda again operating in Afghanistan and the so-called Islamic State gaining a foothold, Washington is also eager to retain a small number of bases from which it can mount counter-terrorist operations.
Whatever the hopes of a full US withdrawal, it now looks as though Washington is set to have a continuing military commitment to Afghanistan, where US air power in particular plays an essential role.