The NATO secretary general made the announcement during a news conference in Brussels on Tuesday, ahead of a meeting of NATO defense ministers later this week.
“We have decided to increase the number of troops … to help the Afghans break the stalemate,” the NATO chief told reporters.
According to Stoltenberg, NATO allies will agree on Thursday to increase by some 3,000 personnel the troop levels for the Afghanistan training mission.
Stoltenberg said that about half of the additional troops will come from the United States and the other half from other countries allied with NATO.
The NATO contribution would take Resolute Support, which is NATO’s train, advise and assist mission, to around 16,000 troops, up from around 13,000 today, Stoltenberg said.
Elsewhere in his remarks, the NATO chief said the troops would not have combat roles but would be part of the Resolute Support.
In February, US Army General John Nicholson, the commander of US forces in Afghanistan, called for more troops, saying that a few thousand more troops would make a difference in weakening the Taliban and other militants.
Under a new strategy announced by US President Donald Trump, thousands of additional US troops will be deployed to the war-ravaged country.
The new deployment is the latest sign that NATO is increasingly being drawn back into fighting in Afghanistan.
US-led forces formally ended the combat mission in Afghanistan in 2014. The United States has about 8,400 troops in the country alongside another 5,000 from NATO forces.
Over the past 16 years, the Taliban militants have been conducting terrorist attacks across Afghanistan, killing and displacing civilians.
In addition, the Daesh Takfiri terrorist group has also gained ground and recruited militants across several provinces of Afghanistan over the past few years.
Afghanistan has been gripped by insecurity since the United States and its allies invaded the country as part of Washington’s so-called war on terror in 2001. Many parts of the country remain plagued by militancy despite the presence of foreign troops.