NATO wants to dramatically scale back its presence in Afghanistan from 16,000 to 12,000 troops, the defence alliance's head Jens Stoltenberg told German broadcaster ZDF on Tuesday.
The United States and the radical Islamist Taliban group, which controls much of Afghanistan, signed an agreement calling for the gradual drawdown of US troops in return for counter-terrorism guarantees over the weekend, after 19 years of war.
NATO had already signalled on Saturday following the announcement of the peace plan that it planned to reduce its own presence, but had not named any figures.
"The road to peace will be long and hard, and therefore everything we do in Afghanistan will be conditions-based," the NATO secretary general said in Brussels.
"We have to see that the Taliban is delivering on their commitments under the agreement," he stressed.
Around half of the 4,000 of the troops to leave Afghanistan would be from the US and the rest from elsewhere, Stoltenberg said.
NATO has been present in Afghanistan since 2001. Its current non-combat mission, launched in 2015, involves training and funding local security forces.
