Secretary-General Anders Fogh Rasmussen told reporters he has sent a fact-finding team to Libya to determine the potential for training and security reform, Stars and Stripes reported.
The team is due to report by the end of June.
Deployment of NATO troops is not under consideration, Rasmussen said, and training of Libyan troops would be done outside the country.
Militias that armed themselves after the fall of Moammar Gadhafi in 2011 currently hold great military power in Libya. One of the groups is the Islamist militia Ansar al-Sharia, which is considered to be responsible for the September 2012 attack on the American Consulate in Benghazi in which the ambassador and three employees were killed.
NATO's bombing campaign was considered instrumental in Gadhafi's ouster, and Rasmussen said Tuesday he thought it would "fitting" to continue that cooperation.
The Libyan military is widely considered as too weak to combat any of the militias, and the flow of weapons from Libya to groups in other countries is also considered a threat.