<p>The Syria Regional Desk of the Diakonia International Humanitarian Law Centre (the Centre) has identified humanitarian access and assistance to areas controlled by non-State armed groups (NSAGs) as an urgent priority. In the context of the Centre’s commitment to improving civilian protection and human rights in armed conflict, this paper was developed to: (1) Provide States, NSAGs, and humanitarian actors with an in-depth overview of the legal and operational aspects related to humanitarian access in situations of armed conflict; (2) Support these actors in improving adherence to international humanitarian law (IHL) and international human rights law (IHRL) with a specific focus on the obligation of NSAGs to facilitate humanitarian assistance through engagement with external actors; and (3) Support humanitarian actors seeking to gain access to affected populations in NSAG-controlled territories to ensure the delivery of essential services to those in need.</p>